The earth is about 4,600 million years old. Modern man has lived on the earth for only 35,000 years, but during that time, we have changed our planet in many ways. Many of the things that we have done are good, but more are not good for the earth.

    Water pollution

    A lot of people, birds and fish die each day because of water pollution. Factories have polluted the land and the water. As a result, many river and lakes are now dead.

    Air pollution

    In big cities, factories, as well as cars, trucks and buses are the biggest cause of air pollution. Many people in cities now have bad health problems. For example, Mexico city used to be a beautiful sunny capital, but today it is almost covered by thick brown clouds.

    Soil pollution

    In order to have a good harvest, most of the farmers use chemicals too much on their fields. That's bad for the soil. But this kind of pollution is difficult to stop.

    Hope for the future

    These problems are very serious for our future, so all of us should do something to improve our environment. If we can stop pollution, our planet will become more and more beautiful and our health will be better. Let's be greener people.

    Almost all animals need to sleep to stay healthy. But sleeping can also be dangerous because other animals may hurt those who are sleeping. This leads to many different ways of sleeping that help them stay safe. Some of these ways may surprise you!

    Almost all bats sleep upside down. They hang from a branch of a tree or the ceiling of a cave. Up high, bats are safe from most other animals. If they are in danger, they just fly away.

    A dolphin sleeps with just half its brain at a time. It must stay awake to breathe and to watch for danger. Dolphin mothers and babies can go without sleep for as long as two months to stay safe.

    Some ducks sleep with just half their brains, too. These ducks often sleep in a line. The ducks at both ends help to keep the group safe. They keep one eye open to watch for danger. The ducks in the middle sleep deeply with both eyes closed.

    Seals breathe air, but that doesn't stop some of them from sleeping underwater. They hold their breath and dive deep to sleep for up to twenty minutes at a time. Sleeping deep underwater helps these seals stay safe from animals that hunt them near the surface.

    Horses often sleep standing up. Their legs lock in place so they don't fall over. If a horse is lying down, it needs a long time to get up. A horse can run from danger more quickly if it is already standing.

    A flamingo can sleep while standing on one leg. The standing leg locks so it stays straight. The other leg remains close to the flamingo's body. Its head rests on its back. A flamingo lives (and sleeps) near many other birds to stay safe.

    Some seabirds can sleep while they fly. These large birds spend most of their lives over the ocean. They are in danger on the water, but they are safe in the air. They fly for many hours without flapping（拍打）their wings. Sometimes they sleep while they are flying.

    Would you like to sleep how they sleep?

    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。

    Recently, many people have begun to try a new way of shopping through the Internet. They are very interested in it. Why is it becoming more and more popular now? There are some reasons. First, more and more people have their own computers and their computers can be joined with the Internet. So it is possible for many of them to do some shopping through the Internet. Second, shopping through the Internet can save some money and a lot of time. Third, they don't need to go to the shop themselves, Because of these good facts, few people refuse it.

However, some people don't like this new way of shopping. They are worried about the safety of shopping online, Customers can only see the pictures of a product on the Internet. And they can't enjoy the pleasure of buying things in a large supermarket or a wonderful shopping centre. These are the reasons why they do not like it.

    But I think more and more people will like this new kind of shopping in the future.

AI could make it less necessary to learn a foreign language. That's good news for travelers, but bad news for soulful connection. Travel has long been one of the reasons for study unless people start to feel AI tools offer a good enough service. 

Some are worried that apps are turning language learning into a weakening need. Douglas Hofstadter, a writer, has argued that something important will disappear when people talk through machines. He describes giving a not so fluent (流畅的) speech in Chinese, which required a lot of work but offered a great sense of achievement in the end. Who would show off taking a plane to the top of Mount Everest? 

  ★  They don't take the weakening as a big deal. Most people do not move abroad or have the kind of continual contact with a foreign culture that requires them to put in the effort to become fluent. Nor do most people learn languages for the purpose of developing themselves or training their brains. On their holiday, they just want a beer or pizza. 

As AI translation becomes a more popular labor-saving tool, people will divide into two groups, just as the above. There will be those who want to challenge their minds, put themselves in other cultures or force their thinking into new ways. This group will take on language learning, often aided by technology. Others will look at learning a new language with a mix of admiration and confusion, as they might say with extreme sports (极限运动): "Good for you, if that's your thing, but a bit painful for my taste."

However, a focus on the learner alone misses the basically social nature of language. It is a bit like discussing the advantages of close relationship to heart health but turning a blind eye to the inner value of those bonds themselves. When you try to ask directions in broken Japanese or make a joke in simple German, you are making direct communication with someone. And when you speak a language well enough to tell a story with perfect timing or put stress on an argument, that connection is till deeper. 

Saving the Earth shouldn't be so difficult if we can do the following things. 

First，we should take our time. There is no need to hurry like doing 100 things a day to save the Earth. Let's start from easy things. For example，we can walk or ride a bike to work. 

Second，we should open the windows more often. Don't turn on the air﹣ conditioner all day. In this way，we can have the fresh air and save the energy. 

Third，we should enjoy cooking at home and having meals at our dinner table. So we can use our own bowls and chopsticks，not the plastic ones. 

Fourth，we should spend our weekends and holidays in the park playing games or just riding a bike around. 

Fifth，we should learn how to make good use of old things in the house，in the garden

Lastly，no one really has a mountain or a sea. Don't throw rubbish here and there. 

All in all，saving the Earth could be easy. Let's take actions to protect the Earth.