16. We must take steps to prevent the __________ world population.

　 A. exploded　 B. exploding　 C. explosion　 D. explosively

15. The amount of money that he saved reached _________ 30000 dollars.

　 A. as many as　 B. as much as　 C. as high as　 D. as far as

14. It is pretty well understood_______controls the flow of carbon dioxide in and out of the atmosphere today．　　

A．that　　 B．when　　 　C．what　　　　 D．which

13. Mary got into acting purely _____________.

　 A. accidental　 B. accident　 C. by accident　 D. with accident

12. It is no use thinking about your ________ youth.

　 A. gone　 B. lost　 C. missed　 D. losing

11. ---Must he come to sign this paper himself?

　 ---Yes．He______ ．

　 A．need　　 B．must　 C．may　　 D．will

10. I wonder how he could __________ not handing in his maths exercises yesterday, for his maths teacher is always strict with his students.

　 A. get along with　 B. get down to　 C. get away with　　 D. get around

9. The basin _______ water soon. You can’t pour more in.

　 A. is full with　 B. fills with　 C. is filled of　 D. is filled with

8. --- I’m very pleased_____ you here；when and how did you come?

　 --- I took a lift this morning．

　 A．to see　　 B．of seeing　 C．seeing D．having seen

7. ---It was a red light, Willian. You __________ the car.

　 ---Sorry. I didn’t see it.

A.　　 must stop　 B. should stop　 C. must have stopped　 D. should have stopped