Choose the underlined part that needs correction in each of the following questions

Exercise 4: Choose the underlined part that needs correction in each of the following questions
1. If you will book before April 30th, you will receive a 20% discount.
D. discount
A. If
C. before
B. will book
2. If we have a bigger flat, we could invite friends to come and stay.
A. have
B. invite
C. to come
3. If the weather were so bad, I could have gone to meet them.
A. were
C. gone
B. so
4. If you worked harder, you will earn more money.
C. harder
A. If
B. more
5. He would not have been arrested if he informed the police after the robbery.
C. informed
A. arrested
D. after
B. if
D. to meet
6. If I had been sent to hospital now, how long would I stay there?
B. had been sent
A. If
C. now
7. What will happen if I will push this button?
A. What
B. will happen
C. if
8. If you had not overslept, you would not missed the train yesterday.
B. overslept
A. If
C. would not missed
9. If she is not careful, she will fall off the bike.
B. not
A. careful
C. she
D. and
D. will earn
D. long
D. will push
D. yesterday
D. will fall