Exercise 1

1 raise

2 gain

3 serious

4 aid

5 wrist

Exercise 2

1 donate

2 save

3 sponsor

4 prescription

5 treat

Exercise 3

1 would stop

2 would you join

3 didn’t hurt

4 didn’t have

5 learned/had learned

Exercise 4

1 Thomas wouldn’t have stayed at home.

2 I would have told him about them.

3 if I hadn’t thought the nurse was wrong.

4 she wouldn’t have gone to the dentist.

5 we had had something for lunch.