The best-known (最熟知的) vegetable in the world is the potato. It grows in many places and does not need rich soil(土壤) like many other crops. But until four hundred years ago, the Europeans(欧洲人) began to know the potato. But today it's one of the main foods in Europe(欧洲). About half of the world's potatoes are grown in Europe.

    In France the potato was not grown for a long time .Here is story about Louis. In 1778 he saw some potato flowers for the first time .He liked them so much that he picked one and put it in his buttonhole. He was interested in the flowers not the potatoes themselves.

    Napoga is a 12-year-old girl in Ghana(加纳), Africa. It is hard for her family to get clean water. Every morning, she leaves home at half past five to get clean water for her family in a village far away. It takes her six hours to get enough clean water for daily(日常) cooking and drinking. She has no time to go to school or to play with her friends. Millions of people in the world are like Napoga. They can't get enough clean water to keep healthy.

    Earth Day is on April 22. But on all other days, we must also remember it. The water we use is the most important natural resource(自然资源) on the earth.

    Water covers 70% of the earth's surface(表面). But most of that is sea water. We can't use it for very many things. Fresh water covers only 1% of the earth's surface.

    You probably feel lucky that your life isn't as hard as Napoga's. But that doesn't mean you don't have to worry about water. We all face serious water problems. One of them is water pollution. All kinds of things from cars, factories, farms and homes make our rivers, lakes, and oceans dirty. Polluted water is very bad for people to drink. And dirty water is bad for fish, too. Now, 34% of all kinds of fish are dying out.

    How do cars and factories make our water dirty? First, they pollute the air. Then, when it rains, the rain water comes down and makes our drinking water dirty. Dirty rain, called acid rain(酸雨), is also bad for plants, animals and buildings.

    Scientists say that in 30 years, more than half of the people in the world won't have enough clean water. We have to learn how to save more water for ourselves and our children. Here is some advice for saving water:

●Turn off the water while you brush your teeth. You can save as much as 450 liters(升) each month.

●Leaky taps(漏水的龙头) waste a lot of water. Fix them right away!

●You can easily cut your 10-minute showers(沐浴) in half—and you'll be just as clean.

●When you wash dishes, don't let the water run.

●Only wash clothes when you have a lot to wash. If your washing machine isn't full, you're wasting water!

    Smog(雾霾) is a big problem in many Chinese cities. But it seems that besides wearing a mask, few of us know what has caused the smog and what to do to beat it. Chai Jing, a former news hostess with China Central Television, discussed the questions in her documentary Under the Dome.

    The 103 - minute film was published on major Chinese video - sharing websites on Feb 28. In the film, Chai visits polluted places and talks to officials and scientists. She comes to the conclusion that burning too much coal and oil are the main causes of PM2.5 and smog.

    To make things worse, according to Chai, the coal and oil we are burning is of poor quality and don't meet the standards for environmental protection. Therefore they have produced more harmful gas to pollute the air.

    To solve the problem, Chai suggests that we should clean our coal and oil or replace them with cleaner energy such as natural gas. In her film, Chai also pointed out that ordinary people can do something to help control smog too. For example, we live a greener life by using more public traffic. Or if we see things that could harm the environment, we can try to stop it. In one scene from the film, Chai sees a dirt mound in a building site exposed in the air, and asks the person in charge to cover it. When she sees a restaurant cooking without any suitable filter facilities, she calls the hotline 12369. The restaurant installed the filter a week later.

    Chen Jining, the new minister of environmental protection, praised Chai. "This film encourages ordinary people to care about the environment. This is what we need in the future. "

    China isn't well known for its science fiction films, but recently a new film called The Wandering Earth has become a great success. It has earned over $697 million worldwide. It tells an amazing story of the Earth in danger, along with exciting scenes of spaceships and outer space.

    The Wandering Earth is based on a story by Liu Cixin. In the story, the sun was dying out, people all around the world worked together to move Earth out of the solar system and sail Earth to a new star system. The film began with the early life of a young boy who was born just after the project started. The engineers pushed Earth away and built underground cities that were vast enough for all the other humans to live in. Yet the 2500 years' journey came with all kinds of dangers. In order to save the humans, a group of young people came out and fought hard for the planet.

    China is playing an increasingly important part in the film industry. Its growing middle class has seen the rise of film market across the country, and Chinese viewers have become an important part of film industry. Hollywood Projects like Iron Man 3 specifically filmed more scenes in China for its market. Chinese film industry is keeping growing. Just as Americans want to get into the Chinese market, Chinese filmmakers are looking for the way to the international market.

    According to The Hollywood Reporter, The Wandering Earth is China's "first space" film. Chinese science fiction writer, Anna Wu, says science fiction "is a new challenge for the Chinese film industry." Some Chinese filmmakers have achieved a great success at this kind of film, but most of them still have a long way to go.

    Still, Wu notes that within China, "Not all the science fiction films have had success. It still takes time to accept science fictions, and that with the development of our country, people are getting busier, wealthier and more stressed," which creates a perfect environment for this new kind of film and television. The Wandering Earth, she says, is a good example. "I also care about the money it earns, which will affect the future of Chinese science fiction films."

    Big ocean fish have almost been endangered since the start of business fishing in the 1950s. The scientists found that the number of large fish has dropped by 90 percent in the past fifty years. The study took ten years. The researchers collected records from fishing businesses and governments around the world. The magazine Nature published (发表) the findings.

    The scientists say the common way called long line(多钩长线) fishing is especially harmful to large fish. This way includes many fishing lines that are connected (连接) to one boat. If these lines are joined together, they can reach one hundred kilometers. They hold thousands of sharp metal hooks to catch fish. Long line fishing is especially common in the Japanese fishing industry. Records showed that Japanese boats used to catch about ten fish for every one hundred hooks. The study says long line fishing boats now might catch one fish per hundred hooks.

    The scientists say business fishing can destroy groups of fish much faster than in the past. The study suggests that large fish can disappear almost completely from new fishing areas within ten to fifteen years. Ocean life systems could be destroyed.

    It's not the only worry that the number of large fish is becoming smaller and smaller. What's worse, they are smaller in size than their ancestors (祖先).