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?
