III

1) inventions

2)departure

3)flights

4) environmental

5)participants

6) necessary

7) bleed

8) instrution

IV

1) would you mind if i took some photographs?

2)i have not seen her for 2 months

3) the tourists said they liked that place

4) an asked Hanh where she has gone the following weekend

5) it is impossible to  work in those conditions

6) the teacher asked to the students not to throw things away 

7) this question is difficult for us to understand

8) she is looking forward to seeing her grandparents soon

9) mai is always leaving her pen at home

10) the water was not warm enough for them to swim in 

11) do you mind helping me move this table ?

12) the last time we saw each other was 2 years ago

13) something must be done for these poor men 

14) the telephone was invented by Bell in 1876

15) would you mind not smoking in the kitchen ?

16) i have not played tennis since 1876

17) it is impossible for rose to grow such poor ground

18 ) the man told Nam that the clock would be never work if he tried to repair it 

19)Trung is given a microcomputer on his birthday  by his parents

20)it is very interesting to have a vacation aboard