15. ________ I came into the office, the teacher were having a meeting.

A.　　 While　　　 B. When　　 C. Once　　　 D. Since

14.The boy didn’t stop talking ________ the second bell rang.

A.　　 when　　 B. until　　　　 C. after　　　 　　　D. because

13.His brother has worked there ________ he left school.

A.　　 when　　 B. after　　　 C. since　　　　　 D. until

12.The light went out while we ________ supper.

A. had　　　 B. had had　　　　 C. were having　　　　 D. would have

11.________ he failed , he went on doing the experiment.

A. Even　　　 B. Yet　　　　 C. Although　　 D. in spite of

10.Write clearly ________ your teacher can understand you correctly.

A. since　　　 B. for　　　　 C. because　　 D. so that

9. You will not succeeded if you ________ harder.

A. will work　　　 B. won’t work　　　　 C. work　　　　　 D. don’t work

8. English is ________ a useful language ________ it is spoken in many countries of the world.

A. so…that　　 B. such…that　　　 C. so…because　　 D. such…because

7. She was busy, ________ she couldn’t go to your birthday party last night.

A. and　　　　 B. so　　　　 C. or　　　　　 D. but

6. Would you give Johnny this letter if you ________ to see him this week.

A. will happen　　 B. happen　　　　 C. are happened　　　　 D. happened