4. It^,s a hard task to protect our environment, so we can’t choose but make an effort.

3. -How about going to see a film tonight?

-I couldn’t agree more.

2. It was time for break and students came out of the classroom one after another.

B. 1. Because　 2. for　 3. Since　 4. As

C. 1. much too　 2. too much

7. urgent　 8. frightening　 9. protection　 10. recycle

10. -Hurry up. We are supposed to reach the station before 7:00.

-　　　 . The traffic in this city is heavy during the rush hour.

A. That’s definite

B. It’s absolutely hopeless

C. I have no idea

D. It’s scary

9. The heaviest flood of all time struck Chongqing city last year and large amounts of farmland 　　　.

A. has been ruined

B. had ruined

C. have been ruined

D. had been ruined

8. -What do you think are the main environmental problems for us now?

-　　　 , the most urgent problem of all is global warming.

A. After all

B. In a nutshell

C. By the way

D. What’s more