Doctors _____ a cure to AIDS yet

1. Doctors _____ a cure to AIDS yet.
A. have found
B. found
C. haven't found
D. hasn't found
2. Do you mind _____ up?
A. wash
B. washing
C. washed
D. to wash.
3. He _____ to give up smoking since last week.
A. was trying
B. have tried
C. has tried
D. tried.
4. He enjoys _____ in the rain.
A. walk
B. walks
C. to walk
D. walking.
5. Would you like _____ to my party?
A. come
B. to come
C. coming
D. came.
6. My sister likes _____ and _____.
A. dance/ sing
B. to dance/ sings
C. dancing/ singing
D. dancing/ to sing
7. This school _____ ten years ago.
A. be built
B. is built
C. was built
D. built
8. He _____ since the day we left school.
A. hasn't seen
B. hasn't been
C. wasn't seen
D. hasn't been seen