C. The professors .(answer) about 100 questions.

might be............................

1-a

2-a

3-c

4-b

5-a

1haven't played

  was

2visited

  went

3have chosen

  bought

4have see

  watchedn

5forgot

didn't say

6 has broken

  fell

  did sell

saw, have bought

8 finished

painted, put up

9have lost

ran