Many of us enjoy watching animals in the world. But do you know they can teach us?

    Geese(雁), for example, teach a very good lesson about 1. In the fall, Canada geese fly to the warm south to 2 Canada's cold winter. They lift off in no order. Yet 3 they form a V shape, with one bird leading the group.

    This V shape allows geese to 4 energy. When the front bird moves its wings up and down, the resulting force of the air lifts the next one. This continues down the line. The bird 5 has the hardest job. When it gets6 , it moves behind, and another bird moves into the lead. By sharing the role, the group can travel great distances. Geese flying in a V shape can fly 70 per cent farther without 7 than birds flying alone. During the long flying journey, geese communicate with one another. They honk(鸣叫) to 8 the birds up front to keep up the speed. They also cheer each other up 9 working toward a common goal.

    What have we learned from the lovely geese's experience and skills?

    10 together! Whether it is our personal lives or our jobs, we need other people. We need the spirit of teamwork!

    Many people know Shanghai's beautiful night view(景色), especially the colorful lights from the buildings. Light helps us see and makes the environment more beautiful. However, too much light becomes a kind of pollution but many of us pay little attention to this pollution or even ignore it. In fact, it causes a lot of problems. Light pollution can be almost as bad as carbon dioxide pollution.

    Too much light can do harm to our health. First, it can make us feel bad and we can't sleep well. Second, lights need electricity, and creating electricity will give off greenhouse gases. This affects the air and causes breathing problems. Third, study shows people living under bright light for long can have cancer more easily.

    Too much light may be even harmful to wild animals. Thousands of birds die from it each year. Some hit into the light buildings, because they can't see clearly in the strong light. Some birds sometimes lose their ways in the bright light Sea turtles(海龟) can't find the dark beaches to lay their eggs.

    To protect humans and wildlife, we should take measures to reduce the use of lights at night.

The Vine That Ate the South

    Kudzu is a fast-growing vine (蔓生植物) that covers a large area in the southern United States. It is so common that one might think it is a native plant, but it is not. Kudzu was brought to the United States from Japan in 1876. Many Americans thought it was beautiful, and they began to plant it. They didn't know it could grow up to a foot a day during the summer months. Nor did they know it would grow up and over anything in its path (路径).

    In Japan, kudzu experienced cold winters and a short growing season. But in the United States, it has a very long growing season with warm and wet southern weather. It is fine weather for the vine to grow fast.

    In the 1920s, people used the vine to feed farm animals. Ten years later, the government supported to plant kudzu because it kept soil (土壤) from washing away. However, by the 1950s, the government no longer wanted people to plant the vine. Twenty years after that, the government said it was a harmful plant.

    The vine grows up trees and buildings, making some beautiful shapes. However, trees die after kudzu covers them because they cannot get enough light. Scientists are looking for ways to kill the vine. They used poisons (毒药)to kill the vine. However, some of the poisons made it grow even better. Scientists also find it difficult to dig up Kudzu. The plant is really tough.

    Because kudzu is so hard to kill, some people are making the best of it. So they try to find different uses for the vine. They find the vine can be used to make paper and baskets, it can be used to feed the goats, and it can even be eaten by people. Scientists are studying it in the hope that the vine can be used as a medicine. At the very least, kudzu serves as an example of the unexpected results that can come from non-native plants.