Butterflies are common all over the world，but butterflies in hotter countries are usually bigger and more brightly colored than those in cooler countries，and there are more different kinds．

   Usually the male butterflies are more brightly colored than the females．The females have bigger and heavier bodies since they carry the eggs．The bright colors of the males help to attract the females，and the duller colors of the females make them less likely to be caught by enemies before they have laid their eggs．

   Some butterflies have bright pattern colors on the upper surface of their wings that show when flying ,but when they rest on a tree or leaves , they close their wings．On the undersides of their wings there are green and brown marks which look like the tree or leaves．They are then difficult to be seen．The best example of this is the Dead Leaf Butterfly．When its wings are c1osed，it looks exactly like a dead leaf．There are even marks that look like the holes in a dead leaf．When the butterfly is run after by a bird，it closes its wings and seems to have disappeared completely．

Under the beauty of their colorful covers, the butterflies have their own way to avoid being killed by their enemies. So do the other animals. That's the rules of the nature and also the gifts that were born with.Many butterflies have round marks on their wings that look like eyes.The round marks have a useful function(功能)．When the butterflies are resting，their wings are closed，and these marks can't be seen. When a bird sees one，and begins to attack it，the butterfly will open its Wings. The bird thinks that it sees two eyes staring at it，frightened，and flies away.

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    What is a Chinatown? Is it a town in China? Of course not! It is in a foreign(外国的) country. It is a place where many overseas(海外的) Chinese live together.

    There are lots of Chinatowns in America. The biggest one is in New York. There are about 150,000 people in it. It is the home of Chinese New Yorkers. And it is also a good place to go.

    Shopping in Chinatown

    Shopping in Chinatown is fun. You can find lots of things there. Most of them are made in China. Mott Street is the best place to shop because the things there are very cheap.

    Eating in Chinatown

    Chinatown has more than 200 restaurants. You can enjoy traditional (传统的) Chinese food there. New Silver Palace Restaurant is one of the best restaurants. Why don't you have breakfast with a cup of green tea in it? You can eat some Shanghai food in Evergreen Restaurant.

    Living in Chinatown

    Living in Chinatown is comfortable. You can find hospitals, schools, banks, libraries and supermarkets in it. In some schools, students must study Chinese. Many overseas Chinese send their children to these schools. They want their children to learn more about China and its culture(文化).

    Scientists have been experimenting with four-leg robots for years. They want to use robots to carry heavy things over difficult land.

    But providing enough power for those kinds of robots has been a problem. Now, that has changed. Engineers at MIT have designed a running robot that runs on batteries. Scientists say their robots will soon be able to run like cheetahs, the fastest land animals on Earth.

    One difficulty in designing these types of robots continues to be providing power. These machines are still quite heavy and they need a lot of power to run. But the cheetah-like robot designed by engineers at MIT is light enough m run on batteries. The robot weighs just 30 kilograms. The robot needs only about 700 watts of power to run. This robot can actually jump 40cm high and it can land very safely and then it can run. The robots limbs and other parts were made in a three-dimensional or 3D printer. A strong, light-weight material called Kevlar is used to make the robot's part stronger.

    But the development of MITs robot is not without its own set of problems. The robot's limbs must support heavy force, and sometimes they break.

    Scientists say the new technologies used on this robot may be used in the making of limbs for disabled persons and other machines. Some of those machines may help save humans from performing difficult and dangerous jobs.

    In 1826, a Frenchman named Niepce needed pictures for his business .But he was not a good artist .So he invented a very simple camera. He put it in a window of his house and took a picture of his garden .That was the first photo.

    The next important date in the history of photography was in 1837. That year, Daguerre, another Frenchman, took a picture of his reading room .He used a new kind of camera in a different way. In his picture you could see everything very clearly, even the smallest thing. This kind of photo was called a Daguerreotype.

    Soon, other people began to use Daguerre's way. Travelers brought back wonderful photos from all around the world .people took picture of famous buildings, cities and mountains.

    In about 1840, photography was improved .Then photographers could take pictures of people and moving things .That was not simple .The photographers had to carry a lot of films and other machines. But this did not stop them, for example, some in the United States worked so hard. Mathew Brady was a famous American photographer. He took many pictures of great people .The pictures were unusual because they were very lifelike.

    Photographers also became one kind of art by the end of the 19th century. Some photos were not just copies of the real world .They showed feelings like other kinds of art.

    Give your dead batteries a new life. Recycle them！

    Batteries(电池) are used to power clocks, computers, tools and more. However,

Your batteries have some serious power when their lives are over.

WHY TO RECYCLE BATTERIES

    Remember, batteries are harmful waste. This mean you could properly throw away. You may not think one little battery can cause that much pollution. But don't think of it as just one battery—there can be millions. In Canada, each person uses about 20 single-use batteries every year. That's about 700 million batteries! If all these batteries end up in landfills(垃圾填埋场), the heavy metals inside them can get into the water, land and air. It can be harmful to humans and wildlife.

    By recycling single-use batteries instead of throwing them away, you can cut down pollution and also help save energy. All batteries are mainly made of plastic and valuable metals. Through recycling programs, dead batteries can be changed into something useful like steel products, or even new batteries!

    HOW TO RECYCLE BATTERIES:

    Make a difference by starting to collect batteries at your home or school today. You can prepare a box for battery collection and invite friends, family and classmates to bring in old batteries to be recycled.

    There are many safe ways to deal with your batteries. You can:

    Find a Call 2 Recycle public collection station near you.

    Ask the store where you bought the batteries if you can return them there.

    Communicate with your local city government to find out if there are special programs for recycling used batteries!

    For more information, visit https://ecokids.ca/batteries.