IV,
1, at / at
2, on
3, in
4, for
5, in
6, to
7, at
8, in

EX 16:
1, This exercise can't be done by us.
2, These clothes have to be washed carefully by her.
3, A car is going to be bought by me.
4, When he came, my homework had been finished by me.
5, The board is being cleaned by her.
6, When she came, my clothes were being washed.

EX 15:
1, Their car is cleaned one a week.
2, Flowers are being cut by her.
3, My bike will be repaired next week.
4, This exercise has to be finished on time.
5, A hotel is going to be built near here.

EX4:
1, have just gone
2, have learnt
3, have they been living / have they lived
4, have lived / have been living
5, Have you been / have never been
6, have known
7, didn't see / have you had
8, has already finished
9, Do you see
10, have been living
11, Have you ever had
12, have been living
13, finished
14, heard
15, have seen
16, have read