题目内容：

首字母填空

April 22 is the World Earth Day. It's a day for us to take c1.of the earth. So what can we do to help? Around the world, many cities and countries find ways to make t2. green.

First, Chicago is f3. for its green roofs. There are plants on these roofs. These p4.store much rainwater. Later, the water goes back to the air to make the city c5.and cool. S6., Singapore has the first zero-energy building in South-east Asia. Zero-energy m7.a building makes more energy than it uses. Third, Curitiba, Brazil, has BRT. BRT runs on special lanes（车道）, so it will always be on time, even in t8. jams. Thanks to BRT, the air in the city is very clean. Today, many other countries have BRT, such as China and Mexico.

Now, pollution（污染）is a big p9. around the world. Please remember we o10.have one earth, and now, it is time for us to protect it.