III. Fill in the blanks with “since” or “for”:
1. It has been raining ................................... lunchtime.
2. My boss will go away ................................... the next ten days.
3. I'm staying in England ................................... a year.
4. She has lived in London ................................... 1985.
5. Please hurry up! We have been waiting ................................... an hour.
6. I have known her ................................... January.
7. Nam's father has worked in this company ................................... 20 years.
8. Have you learned English ................................... a long time?
9. I haven't seen Tom ................................... we left school.
10. The house is very dirty. We haven't cleaned it ................................... years.
11. My sister has been a student ................................... two years.
12. We've lived here ................................... 1990.
13. I haven't seen Linh ................................... my birthday party.
14. She has been away ................................... a year.
15. We've already waited ................................... five days.
16. They haven't had any rain ................................... very long time.
17. That buildings has been there ................................... the 19th century.
18. I have known them ................................... many years.
19. They have only been there ................................... a few minutes.
20. My brother works for a company called FPT. He has worked for them ................................... he graduated from university.