Giải chi tiết:

1. The windows haven't been cleaned for 3 months.
2. I haven't taken photographs for 3 years.
3. I haven't watched TV since New Year's Day.
4. He hasn't written to me for 3 months.
5. I haven't been aboard since the summer of 1978.
6. That house hasn't been lived in for ten years.
7. I haven't seen him for 2 months.
8. The last time I went to a concert was over a year ago.
9. I haven't enjoyed myself since your birthday party.
10. My father hasn't seen his brother for nearly 20 years.
11. How long is it since you learned to drive?

It's 3 months since since the windows were cleaned.

ð The windows haven’t been cleaned for 3months.

7.     It's years since I took photographs.

ð I haven’t taken photographs for years.

8.     I last watched TV on new years's day.

ð I haven’t watched TV since new years's day.

9.     It's 3 months since he wrote to me.

ð He hasn’t written to me for 3 months.

10.                        The last time I was aboard was in the summer of 1978.

ð I haven’t been aboard since the summer of 1978.

11.                        It's ten years since that house was lived in.

ð That house has been lived in for 10 years.

12.                        I haven't seen him for 2 months.

ð I last saw him 2 months ago.

13.                        I haven't been to a concert for over a year.

ð The last time I was to a concert was over a year ago.

14.                        The last time I really enjoyed myself was your birthday party.

ð I haven’t enjoyed myself since your birthday party.

15.                        It's nearly 20 years since my father saw his brother.

ð My father hasn’t seen his brother for nearly 20 years.

16.                        It is impossible for me to call hin at the time

ð I need to call him at the time.

17.                         I advise you to take timely action to protect yourself from harm

ð You should take timely action to protect yourself form harm.

18.                        It is unnecessary for us to wear uniform to the party.

ð We don't have to wear uniform to the party.

19.                        It is required that everyone join hands to do schoolwork.

ð Everyone has to join hands to do schoolwork.

20.                        I am not sure whether he will come or not .

ð He will be able to come or not.

1. The windows haven't been cleaned for 3 months.
2. I haven't taken photographs for 3 years.
3. I haven't watched TV since New Year's Day.
4. He hasn't written to me for 3 months.
5. I haven't been abroad since the summer of 1978.
6. That house hasn't been lived in for ten years.
7. I last saw him 2 months ago.
8. The last time I went to a concert was over a year ago.
9. I haven't really enjoyed myself since your birthday party.
10. My father hasn't seen his brother for nearly 20 years.
11. How long is it since you learned to drive?

1. I haven't seen you in a long time.
2. The windows haven't been cleaned for 3 months.
3. I haven't taken photographs for 3 years.
4. I haven't watched TV since New Year's Day.
5. He hasn't written to me for 3 months.
6. I haven't been abroad since the summer of 1978.
7. That house hasn't been lived in for ten years.
8. I last saw him 2 months ago.
9. The last time I went to a concert was over a year ago.
10. I haven't really enjoyed myself since your birthday party.
11. My father hasn't seen his brother for nearly 20 years.
12. How long is it since you learned to drive?