1. if she leaves now, she (not be)....late
2. if people don't protect the animals, they (kill)....
3. If you ( not pass)...the driving test, we will be disappointed
4. what ( happen)..if the pollution goes on?
5. if they ( stop)...using dynamite for fishing, a lot of aquatic creatures will be well-preserved
6. if pollution increases, more and trees (die)...
7. if it rains tonight, he ( not go )...for a walk
8. if Mai ( be )... late, we ( wait )... for her
9. No one ( help )...him if he ( not help).. himself
10. if the Earth ( be )...warmer, the sea level (rise)...
11. unless it ( rain)...,we will go shopping
12. unless Lan (have)..something to do, she won't  stay at home
13. you will be late if you ( not hurry)...
14. unless she (study)..hard< she will fail the exam
15. we ( go)..out if the rain ( stop)..
16.If people ( use)..the car all the time, they ( make)...the air dirty
17. if we (not,waste)...so much paper, a lot of tress ( save)...
18. You ( remember)...all the answers if you're  more patient
19. if you see some students throw trash in the class, what you ( do )....?
20. if people plant more trees, the air ( not,pollute).....

1.be hard-working and you will be successful 

-> If

2. do more exercise and you will be healthy

->If

3.hurry up and you will arrive at school in time

->I wish

4.recycle wastep aper more, and we can save thousands of trees

->If

5. finish the profect today and we will have a day of tomorrow

->If

6. Join environmental profects more often, and we can help save the Earth

->If

7.do more exercise, and you can stay heathy and keepfit

-> If

8. go to bed early, and you will feel fresh in the morning

-> If you

9. go to the nearest  bookstore and you can easily buy one 

-> If you

10. go to the link and you can find many useful things for you groupwork

-> If you

11. read the instructions carefully or you many misuse it

-> If you

12. Send me messages and I'll give you more details

-> If you

2.'' How long has your son learnt English?," I said to Mrs. Kent ->I asked Mrs. Kent 3." When will you go back?," said Susan ->Susan asked 4.'' What will you by the day after tomorrow, Helen?" said the mother ->the mother 5.'' Have you been to Ha Long yet?" John wanted to know -> John wanted to know 6." Are you working as well studying?" asked Peter -> Peter asked 7." What are you going to study?" asked Ann -> Ann asked 8.'' why has the 2.30 train been cancelled?" said William -> William wanted to know