1 would save

2. will have 

3. won" t pass

4 didn"t smoke

5. had come\ leaved

6. had finish 

7. built

8.sent

9.arrived / had waited

10.isn"t

11. pollution

12 were destroyed

13. would do

14. leaving / came

15 . lived / would speak

16. was sleeping/ rang

17.will not lose / eat

18was built 

19 . had leave 

 20 had gone / went

21.have been visited

22. have

23.don't break 

24. continues 

25 watched/have done

1. We (save) ________would save_______ electricity if we didn’t pay much money.

2. If we use water carefully, more people (have) ________will have________ fresh water.

3. You (not pass) __________will not pass____________ your driving test unless you drive more carefully.

4. He wouldn’t be ill if he (smoke) ___________smokes_______________ a lot.

5. By the time the police (come) ________came_____________, the thief (leave) __had left___

6. After I (finish) ________had finished___________ the lesson, Lan went out.

7. They (build) __________was built_____________ this house in 2015.

8. They (send) ______sent__________ the boys to the orphanage when their parents died of the accident.

9. By the time I (arrive) ________arrived________ the airport, my husband( wait) ______had waited_________ for me for an hour.

10. If the trees (be not) _________aren't______________ watered daily, they will die.

11. Air (pollute) ________polution_____________ is not good for our health.

12. Many houeses (destroy) _________was destroyed______________ in the hurricane last night in Nghe An.

13. If the students reviewed all lessons, They (do) _________will do______________ the test well.

14. After the thief (leave) __had left___ the house, the police (come) __came___

15. If Billy (live) __lives___ in Mexico, He (speak) __will speak___ Spanish.

16. While Bob (sleep) __was sleeping___ the phone (ring) __rang___

17. You (not lose) __won't lose___ weight, If you (eat) __eat___ too much junk food

18. This house (build ) __was built___ in 2000.

19. Most people (leave) __had left___ before the volcano erupted.

20. Last night, Peter (go) ___had gone__ to the supermarket before he (go) __went___ home.

21. Four countries (visit) __have been visited___ by Mr. Brown so far.

22. London (have) __had___ a population of eight million people.

23. If you (not break) __don't break___ the rules, the teacher will not punish you.

24. If the factory (continue) __continues___ dumping poison into the lake, all the fish and other aquatic animals will die.

25. Before she (watch) __watched___ TV, she (do) __had done___ homework.