Scratch is the best educational programming software available today. No other tool makes programming as easy as Scratch does. Many similar products have been inspired by Scratch, but Scratch remains the most popular. With Scratch, you can create interactive games, animations, and science projects, all while having lots of fun!

Scratch is a free programming environment that runs in your web browser. It was designed by the MIT Media Lab’s Lifelong Kindergarten Group. Scratch users, called Scratchers, can create programs by snapping together code blocks in the Scratch editor. Although Scratch was designed for 8- to 16-year-olds, Scratchers consist of people of all ages, including younger children with their parents. The software makes it easy for anyone to start developing their programming and problem-solving skills.


Because Scratch runs in your web browser, there’s no software to install. It’s impossible for a Scratch program to damage the files on your computer. Scratch is completely free—there are no ads or in-app purchases, so kids can play with everything on the Scratch site and adults don’t have to worry about accidental charges.

In Scratch, you use the mouse to drag and drop code blocks, so little typing is needed. Here’s an example of the snap-together code blocks:


The visual Scratch editor provides you with quick feedback, so you don’t have to type mysterious commands for hours before you can see your programs come to life. Scratch makes programming immediate and fun. And unlike other programming languages, Scratch doesn’t have any error messages that pop up and confuse the programmer. If you want to learn the basics of programming (or help someone else learn), Scratch is second to none.

To start using Scratch, open your web browser and go to It doesn’t matter whether you’re running Windows, OS X, or Linux, but you do have to run Scratch on a laptop or desktop computer. Scratch doesn’t work on tablets or smartphones.


The Raspberry Pi computer cannot run Scratch 2.0, the version of Scratch covered in this book.

Signing up for an account is free. You can create Scratch programs without an account, but having the Scratch account lets you save your programs online. Then you can continue working on them later from any computer connected to the internet.

Click the Join Scratch link at the top of the page to create an account. A new window opens:


Choose a username and password, and enter your account information. Scratch will never share your email address or personal information without your permission. Its full privacy policy is at

After you’ve logged in to the Scratch website, click the Create link at the top of the page to start the Scratch editor.

The offline editor lets you program without being connected to the internet. If you don’t have internet access or if your Wi-Fi is unreliable, you can install the offline editor on your computer instead of using the Scratch website. The only difference is that programs will be saved on your computer instead of on the Scratch website. You can later upload your Scratch programs or copy them to a flash drive to move them to another computer.

The Scratch offline editor is available at


You may find the editor software for an earlier version, Scratch 1.4. Don’t use this version; it’s out-of-date and doesn’t have the new features that Scratch 2.0 has. If you’re using Scratch in your web browser, you’re using Scratch 2.0. If you download an offline Scratch editor, be sure to download Scratch 2.0.

The Scratch editor is where you snap code blocks together to create your game, animation, or artwork. The Create link at the top of the page opens the editor, as shown in the following figure, so you can start making Scratch programs.


The most basic object in Scratch is the sprite. Sprites appear on the Stage , and their code blocks control their behavior. The editor automatically starts with a cat sprite for all new projects, but you can add more sprites. You can program a sprite by adding code blocks to the Scripts Area  on the right side of the screen. In Scratch, a stack of code blocks is called a script.

The text field at the top of the editor contains the project name . After you’ve named your project using a descriptive name, remember to occasionally save your project by clicking File image Save Nowfrom the menu bar  to avoid losing your work if your browser crashes.

You access the code blocks from the Blocks Area  in the center. At the top of the Blocks Area are 10 categories of code blocks: Motion, Looks, Sound, Pen, Data, Events, Control, Sensing, Operators, and More Blocks. Every code block belongs to one category and is the color of that category. For example, the say block comes from the purple Looks category. An infinite supply of code blocks is available; just drag them from the Blocks Area to the Scripts Area.

Each sprite has its own scripts. When you click the sprite in the Sprite List , that sprite’s scripts will display in the Scripts Area. Select the Scripts tab  to display the Scripts Area. The Scripts Area is replaced by the Paint Editor and Sound Editor when the Costumes and Sounds tabs are selected, respectively.

Clicking the green flag will start your program, and clicking the red stop sign will stop it .

There are a few ways to get sprites into your programs. You can use the sprites that come with Scratch, upload sprites from your computer, or draw your own. If you want to draw your own, you can use Scratch’s Paint Editor.


The Paint Editor is similar to other painting programs, such as Microsoft Paint or Paintbrush. To draw a new sprite, click the Paintbrush button next to New sprite. You can change how sprites look by switching to one of many costumes. To create a new costume for a sprite, click the Costumes tab, and then click the Paintbrush button next to New Costume.

The main parts of the Paint Editor are

image The drawing tools, which you can select using the buttons on the left side

image The Canvas, where you draw images

image The Costume center, which indicates the center of the costume with the crosshairs symbol

image The Line width slider, which sets the width of the drawing tools

image The Color selector, which changes the color of the drawing tools

image The Zoom buttons for zooming into or out of the canvas

image The Undo and Redo buttons, which can help you correct mistakes

The Paint Editor looks like this:


Experiment with the Paint Editor by clicking the drawing tool buttons and dragging the mouse over the Canvas to see how the tools work. Change the color and width of the drawing tools with the Color selector and Line width slider. Then use the Eyedropper tool to select a color from the Canvas rather than picking a color from the Color selector. If you make a mistake, click the Undo button at the top.

The list of sprite costumes is in the column to the left of the drawing tools. If you want to save a costume as an image file, right-click the costume and select Save to local file.

Before you begin programming, it’s good to get an idea of how the code blocks snap together in the editor. Throughout this book, you’ll learn what each code block does.

To create a new code block, drag it from the center Blocks Area to the Scripts Area. The code blocks that have a notch on top and bump on the bottom are called stack blocks. To snap a stack block together with another stack block, drag the block close to the bottom of the other. When a white outline appears, drop the block to connect it to the stack.


Stack blocks can also fit in between blocks. Look carefully at where the white outline appears in the script: this is where the block will snap into place. This figure shows a wait 1 secs block being moved into the middle of a script:


You can change a white field inside a block by clicking the white area and entering new input. The rectangular white fields accept text; the rounded white fields accept numbers.

The rounded blocks are called reporter blocks. They fit inside the white fields. For example, in the following figure, the green pick random 1 to 10 block fits inside the white field. When the left edgeof the reporter block is over the white field, a white outline appears around the white field. If the left edge isn’t over the white field, the white outline won’t appear and the reporter block cannot be placed inside.


To remove blocks, drag them out of the script. If you remove a stack block, you’ll also remove the stack blocks connected under it, as shown in the next figure. You may need to set aside these blocks if you want to reconnect some of them to the script. Drag the blocks you want to delete over the center Blocks Area to remove them from the Stage. You can always add more blocks from the Blocks Area when you need them.


You can also right-click a block and select delete from the menu that appears. However, doing so will also delete all the blocks underneath that block. If you accidentally delete some blocks, you can restore them by selecting Edit image Undelete from the menu bar.

Create the following program by dragging blocks from the Blocks Area to the Scripts Area:


When you click the green flag at the top of the Stage, this program will start. Programs begin at the top block (when green flag clicked) and then run the next code block in the script. In this example, a speech bubble appears above the sprite and displays the word “Hello!” In the forever loop, the sprite moves forward 10 steps and then turns counterclockwise by 15 degrees. When the program gets to the last block, it loops back to the top. All the blocks in the forever block will run in a loop forever. The program stops only when you click the red stop sign.

You can also run a script or block by double-clicking it. But clicking the green flag is the normal way to start your program.

You can have as many sprites and code blocks in your programs as you want. As you create the programming projects in this book, you’ll learn about Scratch’s many different types of code blocks.


When you’re logged in to your Scratch account, click the Share button at the top-right corner of the editor to let other Scratchers see your program. They’ll be able to play your game and leave comments. If Scratchers enjoy playing the game, they can Like and Favorite your program.


Once you’ve finished a project, you can also add it to the Scratch Programming Playground studio. This studio features projects and remixes you and other readers have made. Once you’ve shared your project in Scratch, copy the URL and go to the studio’s page at Click the Add Projects button, paste the URL into the text field, and click Add by URL. Now other readers will be able to view your game in the studio!

Don’t worry if you think your game isn’t good enough. Everyone begins their coding journey with simple games. Most people on the Scratch website are beginners, too. Over 11 million people have shared their programs on the Scratch website, so don’t fret if yours doesn’t get many views. Games can be difficult to find with so many available on the site!

Becoming a super programmer isn’t about knowing all the answers; it’s knowing how to find answers. You can follow the steps for the projects in this book, but you might have questions of your own.

The first place to look for help is in the Scratch editor’s Help section. Click the Question mark button on the right side of the editor to open the Tips window.


In the Tips window, you can learn what a particular code block does by selecting it from the Blocks tab, as shown here:


You can also access and read through several tutorials. Although you can ask for help in the discussion forums, it’s faster to find answers in the Tips window.

You can learn many new techniques by looking at other Scratchers’ code. Find a project you like on the Scratch website, and then click the See inside button, as shown here:


You’re allowed to copy and modify, or remix, other Scratchers’ code. All Scratch programs on the website are automatically released under a Creative Commons license, so you don’t need to ask the original creator for permission, as long as you give them credit. Scratchers often remix each other’s programs to create their own versions.

Still need help and want to talk to other Scratchers? Click the Discuss link at the top of the website to visit the discussion forums.


The Scratch editor is a creative tool with great potential. You’ll see all sorts of Scratch projects on the Scratch website: games, cartoons, simulations, and informative presentation slides.

Now that you know how to access the Scratch website, create an account, use the Scratch and Paint editors, and snap together code blocks into scripts, you’re ready to follow the step-by-step instructions in the rest of this book. If you have questions, be sure to use the Tips window in the Scratch editor and the discussion forums on the Scratch website to find the answers you need.

Let’s start creating your first Scratch program!

Measles and Rubella Vaccination Campaign

Measles and Rubella Vaccination Campaign

India as a part of its global effort has resolved to eliminate Measles and control Rubella/
Congenital Rubella Syndrome by 2020.
In this direction Ministry of Health and Family Welfare has initiated MR (Measles Rubella)
Vaccination Campaign in the age group of 9 months to 15 years in a phased manner
across the Nation.
This campaign has been conducted in 19 states and more than 9 crores children have
been vaccinated. Maharashtra state would be part of the campaign now.
As a part of this vaccination campaign, TMC Health Department in collaboration with
the Education and ICDS department is implementing the MR campaign from 27th November,
2018 onwards.
Measles is a highly infectious, potentially fatal disease mostly affecting children. As per
disease estimate of the year 2016, every year approximately 50,000 children die in India
due to measles related complications. Rubella even though is a mild viral infection affecting
both the children and the adults. If it occurs during pregnancy it can cause severe
lifelong disabilities (Congenital Rubella Syndrome) to the child and a huge socio- economic
burden to the family and society.

Last year approximately 86,000 Measles and 2 lac Rubella cases were reported among
children in India. Now you can protect your child from both these diseases by a simple
step. Give your child the new and effective MR vaccine. The vaccine is free of cost, pretested
and prequalified by WHO and is provided by the Government of India through
the TMC Health Department in Thane, Mumbai.
The vaccine will be available in your school on Thursday, 13th December, 2018. Each
child will be vaccinated using the audio disable syringes which ensure the injection safety
for the child.
All children up to tenth standard must take this additional dose of MR vaccine irrespective
of previous vaccination status. Children who remain unvaccinated at the end of the
campaign will be highly susceptible to disease and its complications in turn.
Please ensure your child gets Measles Rubella vaccine in school and contribute to-wardsthe effort to ELIMINATE MEASLES AND CONTROL RUBELLA.


Scratch is a slide-and-drop programming language for children.

It allows them to explore and experiment with the ideas of computer programming by using “blocks” that are put together to make simple code.

Although made for children 8-16, Scratch can be used to produce simple or complex programs so it is worth learning to use by adults as well.

Scratch is translated into 70+ languages and is used in homes, schools, and after-school clubs in every country in the world.[4] Scratch is often used in teaching coding, computer science, and computational thinking. Teachers also use it as a tool across many other subjects including math, science, history, geography, and art.


Scratch 2.0 development environment and its different areas at startup.
The area where the user can interact with is called the stage area. The stage area features all of the animations, graphics, drawings, and among other visual features. The list of sprites on screen are placed below the stage area to show a list of sprites that are usable for the program. The stage is organized through x and y coordinates, with the center coordinate (0, 0) placed in the center of the stage. The stage is 480 pixels wide and 360 pixels tall, with a range between x=-240 to x=240 in width and a range between y=-180 and y=180 in height.

From left to right, in the upper left area of the screen, there is a stage area, featuring the results (i.e., animations, turtle graphics, etc., everything either in small or normal size, full-screen also available) and all sprites thumbnails listed in the bottom area. The stage uses x and y coordinates, with 0,0 being the stage center. The stage is 480 pixels wide, and 360 pixels tall, x:240 being the far right, x:-240 being the far left, y:180 being the top, and y:-180 being the bottom.


Motion Moves sprites and changes angles and change X and Y values Events Contains event handlers that are placed on the top of each group of blocks
Looks Controls the visuals of the sprite. The sprite may be attached a speech bubble or a thought bubble, the background or sprite can be changed, it can be enlarged or shrunken, it can have transparency, or it can have shading. Control Contains conditional if-else statements, as well as conditional statements “forever”, “repeat”, and “stop”.
Sound Plays sound files and allows the programming of a musical sequence Sensing. These tools are used for directing sprites to interact with the surroundings that the user has created.
Pen Allows the drawing on the canvas by controlling pen width, color, and shade. It also allows the creation of turtle graphics (drawable graphics). Operators Mathematical operators, random number generator, and-or statement that compares sprite positions
Data Deals with declaring variables and lists, as well as for adjusting variables and lists More Blocks Custom procedures (blocks) and external devices control and can import from PicoBoard or Lego WeDo 1.0/2.0


Kiddle is a visual search engine for kids powered by Google, offering safe kids web, image, and video search. Results are vetted by editors.

How is Kiddle designed specifically for kids?
1) Safe search: sites appearing in Kiddle search results satisfy family friendly requirements, as we filter sites with explicit or deceptive content. Please read more on kids safe search on Kiddle here.
2) Kids-oriented results: the boxes below illustrate how Kiddle returns results for each query (in the order shown):
1    Safe sites and pages written specifically for kids. Handpicked and checked by Kiddle editors.
Typically, results 1-3.
2    Safe, trusted sites that are not written specifically for kids, but have content written in a simple way, easy for kids to understand. Handpicked and checked by Kiddle editors.
 3     Safe, famous sites that are written for adults, providing expert content, but are harder for kids to understand. Filtered by Google safe search.
3) Big thumbnails: most Kiddle search results are illustrated with big thumbnails, which makes it easier to scan the results, differentiate between them, and click the most appropriate results to your query. Thumbnails serve as visual clues and are especially beneficial to kids as they don’t read as fast as adults.
4) Large Arial font in Kiddle search results provides better readability for kids.
5) Privacy: we don’t collect any personally identifiable information, and our logs are deleted every 24 hours. Please read our full privacy statement here.



Children’s Day 2018 will be celebrated at Wednesday, on 14th of November.


Children’s day (also known as Bal Divas) in India is celebrated every year on 14th of November to increase the awareness of people towards the rights, care and education of children. Children are the key of success and development of the country as they would lead their country in different and new technological way. They are adorable and shine same like the precious pearls. Children are the God gifts to their parents by the almighty. They are innocent, admirable, pure and loved by everyone.

14th of November (birthday of Pandit Jawaharlal Nehru) has been set to celebrate as children’s day all over the India. 14th of November is the birth date of the first Indian prime minister, Pandit Jawaharlal Nehru. He became the prime minister of India just after the independence of India. The Children’s Day is celebrated every year to let the people specially parents aware about the importance of celebrating this day.


The birthday of Chacha Nehru, a great Indian leader, is celebrated as Children’s Day. He worked great for the well being of children as well as youngsters after the independence of India. He worked so much for the education, progress and welfare of the children of India. He was very affectionate towards children and became famous as Chacha Nehru among them. For the progress and development of the youth of India, he had established various educational institutions such as Indian Institutes of Technology, All India Institute of Medical Sciences and Indian Institutes of Management.

He made a five year plan which includes free primary education, free meals including milk to the school children in order to prevent children from malnutrition in India. The deep love and fervor of Chacha Nehru towards the children is the big reason of celebrating the Children’s Day at his birthday anniversary.

The childhood is the great moments in the life of everybody which should be necessarily given a right track to become successful in the future as an asset of the country. Without the right track they may miss living a good life. This can be done only by giving a right education, care and way to progress.

About Pandit Jawaharlal Nehru

Pandit Jawaharlal Nehru was a great leader of India and led the India as a first prime minister of India just after getting the independence in 1947. He was born on 14th of November in the year 1889 to the renowned lawyer, Mr. Motilal Nehru and Swaroop Rani in the Allahabad. Because of being very brilliant he was named as Jawaharlal. He got his later education from the England and after returning to India he started helping Indians and struggle for independence of India. After independence of the India he became the first prime minister of the India. He was also a great poet; some of his famous writings are ‘Glimpses of World History’, ‘Discovery of India’ and etc.

He was really fond of children as well as roses that’s he said that children are like the buds of the garden. He said that children are the country’s actual strength as they would make developed society in future.


Children’s day is celebrated every year with a lots organized programs including cultural and fun activities all over the India. Government and non government organizations, schools, NGOs, private bodies and other conducts variety of competitions as well as events for the children to let them known about their rights and make them happy and cheer. TV channels also demonstrate the interesting programs for the children on 14th of November.

Parents take part in this event very enthusiastically to make their children happy; they distribute gifts, greeting cards to their sons and daughters. They go on picnic, long drive and enjoy the day with party.


  • Children are distributed gifts and chocolates.
  • Varieties of competitions are organized like fancy dress, debates, speech related to the freedom fighters, country, storytelling and quizzes.
  • Cultural and social programs like singing, dancing and entertaining with other musical instruments.
  • Orphan children can be entertained by distributing the clothes, toys, musical instruments, stationery, books, and etc.
  • Organizing some programs related to the freedom fighters.
  • Organizing some game activities including puzzle, sweet and sugar treasure hunt and etc.
  • Underprivileged children are entertained by organizing musical programs by famous musician and speech on health, care and progress.


Fredrick Douglass, an American social reformer, writer and statesman one said- ‘It is easier to build strong children than to repair broken men’. A wise quote referring to the role children could play in laying the foundation of a strong nation; a thought also shared by a much respected Indian freedom fighter and the first Prime Minister of India- Pandit Jawaharlal Nehru.

Pt. Nehru strongly believed that the foundation of a strong nation depends on the way its children are cared and nurtured. In order to build a strong nation we must instill good values in our children providing them love and care; guiding them through thick and thin till they become confident and strong enough to contribute in building the nation.

This equation was very well understood and believed by Pt. Nehru; which was displayed in his affection towards children across culture and linguistic barriers. Such was the mutual love and understanding between the children and Nehruji that he was fondly called as ‘Chacha Nehru’ by them.

Children’s Day celebrated on the birth anniversary of Pt. Nehru, is a tribute to him and his belief that ‘the foundation of a strong nation depends on the happy state of its children.’ The noble man is long gone but his thoughts live till today; reminded every year on Children’s Day.

The day reminds us of the importance of well being of our children for the nation as well as society. It also reminds us as responsible citizens of India; not to differentiate between children based on their, caste, religion, ethnicity or financial and social status. It reminds us to protect our children, nourish and nurture them; providing them education, opportunity to grow and good health.

The day also marks celebrations in the schools across India, when various amusement events are organized for the children. Gifts are distributed in schools and children are morally encouraged by speeches and prize distribution ceremonies.

Many social activists and non government organizations organize events in the slum areas of big cities; a noble effort to improve the morale of under privileged children dwelling there and also show them that they are equally cared and loved for.

Related image

Image result for children's day

To know more information go to this hyperlink


The Seven Wonders of the World 

The Seven Wonders of the World (or the Seven Wonders of the Ancient World) is a widely-known list of seven great buildings or structures from the classical time period.

Seven Wonders of the Ancient World

This is a list put together in the 2nd century BC by Antipater of Sidon and Philon of Byzantium. This explains why it only lists monuments of the Mediterranean world. There are other slightly different versions: this is the most usual one.

  • Great Pyramid of Giza (Egyptian). The oldest of the wonders, and the only one still standing.
  • Hanging Gardens of Babylon (Babylonian). Built by Queen Semmu-ramat (= Semi-ramis) or King Nebuchadnazzer II. The exact location of this monument is not known. It was in Mesopotamia.
  • Statue of Zeus at Olympia (Greek). A gigantic statue made of marble, with applied gold leaf.
  • Temple of Artemis (Greek). In Ephesus, Asia Minor (modern Turkey), on the Aegean Sea. It was burnt down by Herostratus in 350 BC. When questioned, he is said to have replied: “To make my name immortal”. First known crime committed for fame.
  • Mausoleum of Maussollos (Persian). Tomb of the Anatolian king of that name, built by his widow Artemisia, at Halicarnassus (present Bodrum, Turkey).
  • Colossus of Rhodes (Greek). Built to commemorate the raising of the siege of Rhodes 304–5 BC. At 30 metres, the tallest statue in the ancient world.
  • Lighthouse of Alexandria (Egyptian/Greek). Called the Pharos, this was built for Ptolemy II, about 280 BC. To this day, ‘Pharos’ is the name for lighthouse in several European languages.

Out of those structures only the Great Pyramid still exists in the 21st century. Most of the wonders were built by the Greeks. Earlier versions listed the Walls of Babylon and the Palace of Cyrus the Great.

Seven wonders of the modern world

This version was decided by the American Society of Civil Engineers.

  • Channel Tunnel (England & France)
  • CN Tower (Toronto, Canada)
  • Empire State Building (New York, United States)
  • Golden Gate Bridge (San Francisco, United States)
  • Itaipu Dam (Brazil/Paraguay)
  • North Sea Protection Works (Netherlands)
  • Panama Canal (Panama)

Seven natural wonders of the world

There is no single list of seven natural wonders of the world. One of the many lists was compiled by CNN:

  • Grand Canyon
  • Great Barrier Reef
  • Harbour of Rio de Janeiro
  • Mount Everest
  • Aurora
  • Parícutin volcano
  • Victoria Falls

New7Wonders of the World

New7 Wonders of the World was an idea to choose new wonders of the world from a selection of 200 existing monuments. The mission began in 2001 and ended in 2007 with the announcement of the winners. The popularity poll was led by Canadian-Swiss Bernard Weber and organized by the New7Wonders Foundation in Zürich, Switzerland. Voting took place through the Internet or by telephone.

The program caused different reactions from countries and organisations. Some countries praised their finalist and tried to get more people to vote for it. Others criticized the contest or did not think it was very important.

Among the strongest criticism was from UNESCO, who said in a press release in 2007:

There is no comparison between Mr. Weber’s mediatised campaign and the scientific and educational work resulting from the inscription of sites on UNESCO’s World Heritage List. The list of the 8 New Wonders of the World will be the result of a private undertaking, reflecting only the opinions of those with access to the Internet and not the entire world. This initiative cannot, in any significant and sustainable manner, contribute to the preservation of sites elected by this public.



  • Great Pyramid of Giza (awarded honorary status)
  • Great Wall of China
  • Petra (Jordan)
  • Colosseum (Rome)
  • Chichen Itza (Yucatán)
  • Machu Picchu (Peru)
  • Taj Mahal (India)
  • Christ the Redeemer (statue in Rio de Janeiro)

Other modern lists

From a variety of modern lists of wonders made by man, some items occur several times:

  • The Taj Mahal, India
  • The Colosseum in Rome
  • The Great Wall of China
  • Stonehenge, England. The only prehistoric site on any list.
  • Machu Picchu, Peru
  • The Hagia Sophia. One of many places of worship which might be candidates.
  • Angkor Wat, Cambodia



Swap it another word for trade


Trade is the buying and selling of goods and services. Goods are objects that people grow or make—for example, food, clothes, and computers. Services are things that people do—for example, banking, communications, and health care. People have traded since prehistoric times. Today most countries take part in international trade, or trade across country borders.


Trade happens because people need or want goods that they do not have. People also trade for services when they do not have the time or the skills to do things. Trade between countries happens for similar reasons. For example, some countries have resources, such as oil, or skills, such as car manufacturing, that other countries will buy.By trading both traders will get benifit.


In some economies, the government controls all trade. In others, the government allows companies to trade more freely. However, even governments that support free trade control trade in some way. They may keep companies from trading dangerous or illegal products. They may also pass laws to prevent companies from forming monopolies. A monopoly occurs when one company has so much control over a certain type of good or service that no other companies can compete.


In the 1900s many countries worked to stop trade limits. Some formed trading blocs, or groups of countries that trade freely. Examples include the North American Free Trade Agreement (NAFTA), the European Union, and South America’s Mercosur. In addition, about 150 countries joined the World Trade Organization (WTO). The WTO encourages free trade around the world.

The lifting of trade limits caused international trade to grow.


Trade developed along with civilization. Before 2000 bc people in the earliest civilizations of Mesopotamia, ancient Egypt, and the Indus Valley traded among themselves and with other peoples. As time passed, civilizations built trade routes. They used these paths to transport spices, salt, gold, and other goods over greater distances. Trade routes went over land and sea.

The Tallest Building in the World


Burj Khalifa or “Khalifa Tower”  is a very tall skyscraper in Dubai, United Arab Emirates and is the world’s tallest building ever built, at 828m (2,717ft). Before the building opened, it was called Burj Dubai. The building is 160 stories high. Construction of the tower was started in 2004. The building was officially opened on 4 January 2010. It is the tallest structure made by humans in the world. The building is more than 300 metres (980 ft) taller than Taipei 101. Taipei 101 was the tallest building until 2010 before Burj Khalifa was built.

Adrian Smith designed the tower. He worked with Skidmore, Owings and Merrill (SOM) until 2006. It was built by Samsung Engineering & Construction, Besix, and Arabtec. The tower cost US $1.5 billion to build. The building is part of a 2 km building project on Sheikh Zayed Road, Downtown Burj Khalifa. It is near Dubai’s main business district.

Records set
The building is not only the tallest structure in the world, it also holds the following records-

  1.    Tallest skyscraper to top of spire: 828 m (2,717 ft) (previously Taipei 101 – 509.2 m (1,671 ft).
  2.   Tallest structure ever built: 828 m (2,717 ft) (previously Warsaw radio mast – 646.38 m (2,121 ft)).
  3. Tallest freestanding structure: 828 m (2,717 ft) (previously CN Tower – 553.3 m (1,815 ft)).
  4. Building with most floors: 160 (previously Willis Tower – 108).
    World’s highest elevator installation.
  5. World’s fastest elevators at speed of 64 km/h (40 mph) or 18 m/s (59 ft/s) (previously Taipei 101 – 16.83 m/s).
  6. Highest vertical concrete pumping (for a building): 606 m (1,988 ft) (previously Taipei 101 – 449.2 m (1,474 ft)).
  7. Highest vertical concrete pumping (for any construction): 606 m (1,988 ft) (previously Riva del Garda Hydroelectric Power Plant – 532 m (1,745 ft)).
  8. The first world’s tallest structure in history to include residential space.
  9. Highest outdoor observation deck in the world (124th floor), at about 440 m (1,440 ft).
  10. World’s highest installation of an aluminium and glass façade, at a height of 512 m (1,680 ft).
  11. World’s highest swimming pool (76th floor).
  12. Worlds highest restaurant (122nd floor).


The Y-shaped tripartite floor geometry is designed to optimize residential and hotel space. A buttressed central core and wings are used to support the height of the building. Although this design was derived from Tower Palace III, the Burj Khalifa’s central core houses all vertical transportation with the exception of egress stairs within each of the wings. The structure also features a cladding system which is designed to withstand Dubai’s hot summer temperatures. It contains a total of 57 elevators and 8 escalators.






Oxygen is the most common chemical element found on or in Earth. It is one of the main elements that make up air, and it is necessary for the survival of all plants and animals. Scientists use symbols to stand for the chemical elements. The symbol for oxygen is O.

Oxygen makes up about one fifth of the atmosphere.

In its free state, oxygen is a gas without color, odor, or taste. It turns into a pale blue liquid at temperatures below –297° F (–183° C) and becomes solid at about –360° F (–218° C). Oxygen combines easily with many other elements to form substances called compounds. The most common compound is water, which is two parts hydrogen to one part oxygen.

All animals need oxygen to stay alive. When they breathe in air, the oxygen in the air combines with the elements carbon and hydrogen in the body. This releases energy that the animals use to survive. The animals then breathe out a compound of carbon and oxygen called carbon dioxide. Plants take in that carbon dioxide as part of a process called photosynthesis.

Image result for breathing in plants

Image result for oxygen respiration

Image result for oxygen


Food & Nutrients


Plants make their own food with the sun’s help. Animals, including humans, do not. Instead they eat food—plants or other animals—to get what their bodies need to live and grow. Nutrition is the science of how the body uses food.

Food gives the body the energy it needs for everything it does, from repairing damaged cells to sleeping. The amount of energy a food can produce is measured in calories. When a person eats more food than the body needs, the body changes the extra calories into . Eating fewer calories than the body needs will cause a person to lose weight.

Food also provides the nutrients that the body needs to function and maintain itself. These nutrients are proteins, carbohydrates, fats, minerals, vitamins, and water.

Proteins are needed for body tissue to grow and repair itself. After water and possibly , protein is the most abundant material in the human body. People can get the protein they need from animals or plants. Animal sources include meat, fish, and eggs. Plant sources include beans, nuts, and grains.

Carbohydrates give the body most of the energy it needs. Starches and sugars are carbohydrates. Starches are found in grains such as rice, wheat, and corn. Potatoes, beans, and other vegetables also contain starch. Sugars are found naturally in fruits, milk, and honey. Refined sugars are made by processing plants such as sugarcane, sugar beets, and corn. Refined sugars are often used to sweeten foods. They are high in calories.

Fiber is another kind of carbohydrate. It does not provide energy, but it is important to the body in other ways. Fiber aids digestion. It also helps people to feel full. In addition, fiber can reduce the level of cholesterol in the blood. Cholesterol is an important substance in the body. However, when the body has too much cholesterol, blood vessels may become lined with fatty deposits.

Fats are sources of energy that the body can store. The fats in foods may be solid or liquid. Liquid fats are called oils. The body uses fats to maintain its temperature and to cushion organs. Fats also help the body use certain vitamins. Cooking oils, nuts, fish, and avocados can be healthy sources of . But some fats can be harmful.

Minerals serve a variety of purposes. Calcium, for example, builds bones and teeth and helps to clot blood. It is found in dairy products, green leafy vegetables, and tofu. Iron is needed to build red blood cells and carry oxygen from the lungs to other body cells. Good sources of iron include meat, egg yolks, and dark green vegetables. Other minerals important to the human body are iodine, magnesium, phosphorus, sodium, potassium.


The body also needs vitamins. Vitamin C keeps gums healthy and helps the body absorb iron. Vitamin D works with calcium and phosphorus to make strong bones and teeth. Other vitamins are A, E, K, and the B-complex vitamins. Vitamins are found in many different foods.

Water is important in many chemical reactions in the body. In fact, every cell in the body must be bathed in water. Water also helps the body get rid of wastes and maintain its temperature. Water makes up about 60 percent of an adult’s body weight.

Different foods contain different combinations of nutrients. Some foods are better sources of nutrients than others. Scientists have created charts and pictures to show how much a person should eat from different food groups in order to be healthy. Many countries have created food group charts in various shapes, including pyramids, pagodas, rainbows, and plates.

In general, scientists recommend that people eat lots of vegetables and fruits. They recommend moderate portions of grains, protein, and dairy products.


Food can sometimes get contaminated or infected with harmful things. A person who eats such food can get an illness called food poisoning. Food poisoning is caused by bacteria and other microorganisms. Once inside the body, these microorganisms release poisons that make people sick. The most common symptoms are fever, stomach cramps, nausea, vomiting, and diarrhea. Most people recover within a few days.