13. It ___ long before China ___ on the moon.　 A. won’t be, will land

B. is, will land　 C. won’t be, lands　　 D. is, lands

12. The child ___ while watching TV. So his mother sent him to bed at once

A. had fallen asleep　 B. was falling asleep　 C. fell asleep　 D. falls asleep

11. --- What ___ when the gang broke in?　 --- I ___ the TV and was going to bed.

A. were you going, was turning off　　 B. did you do, had turned off

C. had you done, was turning off　　 D. were you doing, had turned off

10. Unfortunately when I arrived she ____, so we only had time for a few words.

A. was just leaving　 B. just left　 C. has just left　 D. had just left

9. --- Did Mr. Sung but any reading materials for you when he was in the US?　 --- He was always meaning to, but never ____.　 A. do　　 B. done　 C. did　　 D. does

8. --- Have you finished your design yet, Jack?　 --- No, I ___ my brother all day yesterday.

A. helped　　 B. was helping　 C. has helped　　 D. would help

7. The mobile phone I ___ I ___ is on the back seat of my car.

A. thought, had lost　 B. think, had lost　 C. thought, have lost　 D. think, lost

6. New technology ___ to make sure that the cars, taxis, buses and trains we use ___ the air.

A. is used, not to pollute　 B. has used, is not allowed　 C. is being used, do not pollute　 D. has been used, to pollute

5. Proper first aid can save a seriously injured person, especially when he or she is bleeding heavily or ___.　 A. has poisoned　 B. was poisoned　 C. has been poisoned　 D. is poisoning

4. --- Why didn’t you go to yesterday’s meeting?　 --- I would have, but I ___ too busy working on the important experiment.　 A. had been　　 B. was　　 C. were　　 D. am