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).....