1> If you study hard, your parents will be happy.

2> This river won't be polluted if people don't throw rubbish into it.

3> If he comes late, Lan will be angry.

3> What will you feel if you get good marks?

4> If you give her this book, she will be happy.

5> What will you do if your friend is absent from class?

6> If we don't worried, we will be late.

7> What will you do if you see a man walking around your house?

8> If you don't finish your homework, you can't go home.

9> What will you do if your friend needs for help?

10> What will she do if she meets him at the party?

11> If he doesn't come, we will watch the film.

12> If the weather is bad tomorrow, we will stay at home watching TV.

13> What do your friends do if today is your birthday?

14> She will be sad if you don't talk to her.

15> Will he be happy if you smile with him?

1. if you need a ticket, I can get you one

2. if you come in, he will kill you

3. if David has any money, he spends it

4. if we go home today, we will be having a party tomorrow

5. if you are thirsty, drink a cup of water