Scientists are trying to make the deserts into good land again. They want to bring water into the deserts, so people can live and grow food. They are learning a lot about the deserts. But more and more of the earth is becoming desert all the time. Scientists may not be able to change the desert in time. Why is more and more land becoming desert? Scientists think that people make deserts. People are doing bad things to the earth. Some places on the earth don't get much rain. But they still don't become deserts. This is because some plants are growing there. Small green plants and grass are very important to dry places. Plants don't let the hot sun make the earth even drier. Plants don't let the wind blow the dirt away. When a little bit of rain falls, the plants hold the water. Without plants, the land can become a desert much more easily.

阅读短文回答问题。

    There are some easy things you can do to protect the environment and the earth. Choose ideas from the list or come up with a few of your own.

    ·Plant flowers, grass or trees.

    ·Whenever you visit a park or beach, take away what you bring there-keep rubbish in a bag until you can put it in a dustbin.

    ·Turn off the lights, TV sets when you leave the room. This saves a lot of electricity.

    ·Turn off the tap when you brush your teeth. You can save some water by not letting it run. Also, use a glass cup instead of a paper cup because this saves paper.

    ·Keep the doors and windows closed in winter to keep cold air in.

    ·Give your old books and magazines to a library instead of throwing them away.

    ·Give your old clothes to poor children you know instead of throwing them away.

    ·Use both sides of paper.

    ·Stop pouring dirty water into the rivers or lakes nearby.

    ·Encourage all your friends to do the same things you do to help protect the earth.

    You don't have to wait until Earth Day to do these things. Make every day Earth Day.

    If everyone makes a contribution to protecting the environment, the world will become much more beautiful.

    Bioplastic(生物塑料) is a kind of plastic, but it is not the same as normal plastic. Normal plastic is made from chemical materials and takes a very long time to degrade(降解). But bioplastic is good for the environment. It is made by using bacteria(细菌) to process(加工) natural sources like vegetable oils, corn or sugar. It can degrade more easily.

    But there is a problem with bioplastic. The "food" that bacteria eat is what we eat. This means that bacteria are competing against humans for the same resources.

    Now scientists have found a new way to make bioplastic——using two kinds of bacteria and sunlight, according to Newsweek.

    One of the bacteria can use sunlight to produce sugar. The other kind lives in the salty waters of Bolivia. It eats the sugar that the first bacteria produce and then it can produce polymers(聚合物). Polymers are used to create bioplastics. The way the bacteria store polymers is similar as humans store fats.

    The new way to produce bioplastic has many advantages. It is 20 times faster than the normal way we produce bioplastic. Moreover, using these two bacteria saves resources.

    Firstly, producing a lot of bioplastic requires corn and sugar, which are used to feed normal bacteria. And growing corn and sugar needs farmland. But these two bacteria can just use sunlight. The land that is saved can be used to grow food for humans. Besides, this system doesn't need rich land or clean water at all, scientists said to Newsweek.

    The next problem scientists face is that they want to put their lab research into real-world practice. By doing this, bioplastic made with these two bacteria can be widely produced in the future.

    Inventions usually make a big difference to people's lives. Do you have any great inventions at home? Do they help you a lot in your life or bring you much fun? Here are some of the most useful inventions in families according to a survey.

    Almost every Chinese can recite the famous poem, "Every grain on the plate comes from hard work(谁知盘中餐, 粒粒皆辛苦)."But sadly, many of us don't actually get the real meaning of these lines：Don't waste food.

    A CCTV programme, News One Plus One, reported that the food Chinese people throw away every year is enough to feed 200 million people for a year.

    Do we have too much food? No, according to the UN World Food Programme, there were 925 million hungry people around the world in 2010, especially in developing countries.6 million children die of hunger every year.

    Chinese people are well-known for being generous. Many even feel that they will lose face if their guests have eaten all the food on the table.

    Luckily, a number of people have realized the importance of saving food. In November, 2011, Li Hong, a waitress in a restaurant in Nanjing, became famous because she took some leftover(剩余的)food home for her son. Many people stood by her side and agreed that it was not right to waste food.

    What should we do in our daily lives to save food? Here are some tips：

    Do not order too much in a restaurant. Only order what you want to eat. If you cannot eat all the food you ordered, take the rest of it home.

    Don't be too picky(挑剔的)about food. Some food may not taste great, but your body needs it.

    Keep an eye on what food you have at home. Don't buy too much, especially vegetables and fruit.