In nature, you may see many insects(昆虫) and animals of different colors. Have you ever wondered why?

    Locusts are super delicious food for birds, but it is not always an easy job for birds to catch them. It is neither because locusts are good jumpers or runners nor because they are smarter than their enemies. The reason is that the colors, of locusts change with the colors of crops(庄稼). When crops are young, locusts look green. But when autumn comes, locusts change to the yellow and brown color as crops do.

    Brown bears, tigers and other animals move quietly through forests. They can't be seen easily by their enemies. This is because they have colors similar to the trees. For the same reason, polar bears that live on a land of snow and ice are white. Butterflies and bees living among the flowers are colorful like flowers. Soil insects are mostly dark colored and they live under the soil(土壤)in a dark and wet environment. However, insects with colors different from plants can easily be found and eaten by others. So in order to survive, they have to hide themselves in the daytime and appear only at night.

    Have you ever noticed some even stranger acts? The ink fish in the sea can send out some very black ink when it faces danger. As the ink spreads over, its enemies will find themselves suddenly in a dark world. At the same time the ink fish immediately swims away. That is how it keeps itself safe though it is not strong at all.

    You can be proud of yourselves, even if you can only make one or two of these green changes. The goal here is to limit carbon dioxide and other greenhouse gases, which are closely connected to the big problem of global-warming (全球变暖).

    WAY 1: Bring your own cup to Starbucks. You'll get a 10-cent discount, and it's one less paper cup to end up in a dustbin. The store won't create more waste when they throw away a cup.

    WAY 2: Turn off your computer. When in standby mode, your PC is still using energy. Turning off a monitor (显示器) for 40 hours a week may only save $ 5 a month, but it reduces CO₂ by 750 pounds.

    WAY 3: Reuse plastic bags. Instead of throwing away 100 billion plastic bags a year, try and get a second, third, or tenth use out of them. Better yet, next time you shop, try a reusable bag. The amount of oil it would take to make just 14 plastic bags would run your car for one mile.

    WAY 4: Use recycled paper in the bathroom. Most of the toilet paper we use is made from trees found in forests. If every family replaced(替换)one roll of toilet paper with a recycled one, 424,000 trees would still be standing.

    WAY 5: Plant a tree. Adding green to your garden is beautiful and earth-pleasing. Just one tree will help make cleaner air and save the environment from 5, 000 pounds of hot carbon dioxide each year.

    When you look up into the night sky, you can see the moon. But do you know that you're only seeing one side of the moon? The other side, also known as the far side of the moon, has long been a secret to us. But now, we have a chance to see what's on the far side.

    On January 3rd, China's Chang'e 4 probe(探测器) landed on the far side of the moon. It is the first probe in history to land there.

    Chang'e 4 probe has already done a lot of things on the moon. One of its jobs is to grow plants. Chang'e 4 probe took six living things to the moon. Such as cotton, potatoes and fruit flies(果蝇). The cotton has already started growing. This is the first time humans have grown plants on the moon.

    Chang'e 4 probe also took a lot of pictures of the moon's far side. With these pictures, scientists will learn more about the moon.

    Do you still get free plastic bags from the supermarkets? Things have changed.

    China has banned(禁止) free plastic bags at shops and supermarkets, and people have to pay for using plastic bags. The rule started on 1st June. It came because our country tried to make litter less. Making super­thin(超薄的)plastic bags has also been banned.

    The Chinese once used about 3 billion plastic shopping bags a day, and they have caused pollution of the environment. The bags have become a main cause of plastic pollution because they are easy to break and people throw them away here and there. So the Chinese people are encouraged to bring their own bags for shopping.

    What kind of shopping bag is the best to bring? Some students in Chongqing have a good idea. They make their own shopping bags. They use old clothes to make cloth bags(布袋), and send them to their parents as presents. They also ask their parents and friends to use cloth bags instead of plastic ones. They think it is their duty to protect the environment.