阅读理解。 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 rivers and lakes are now dead. Air pollution In big cities, factories, as well as cars, trucks and buses are the main cause of air pollution. Many people in cities now have serious health problems. For example, Mexico city used to be a beautiful sunny capital, but today it is always covered by thick brown clouds. Soil pollution In order to have a good harvest, most of the farmers use chemicals too much in 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! 1. _____ have made the earth change a lot. [     ] A. Human beings B. Animals C. Plants D. People in other planets 2. There are _____ kinds of pollution in this passage. [     ] A. two B. three C. four D. five 3. Pollution isn't a big problem now, is it? [     ] A. Yes, it is. B. No, it isn't. C. Yes, there is. D. No, there isn't. 4. Which sentence is NOT right according to the passage? [     ] A. Most of things that we have done are good for our planet. B. We must stop the factories from pouring waste water into the rivers and lakes. C. Because of water pollution, many rivers and lakes are now dead. D. Water pollution is very serious nowadays. 5. Which sentence is RIGHT? [     ] A. Though Mexico city is always covered by thick brown clouds, it's still a beautiful sunny capital. B. Air pollution can make people sick. C. Now fewer farmers use chemicals in the fields. D. Factories, cars, trucks and buses are the main cause of soil pollution.