I am learning English because it is international and interesting. You can't will go to university, if you don't know English. If you know English, you will understand many people in different countries and you can know how people lifes
1. We went with our experiments FOR a year. DURING this period of time it became clear that our approach had some disadvantages.
2. Many problems were discussed SINCE the conference and some of them FOR many hours. DURING the discussion different suggestions were made. The conference continued FOR a week.
3. Biology made great progress DURING the second half of the XIX century and FOR some time it was supposed that there is nothing much to be discovered.
4. Man FOR thousands of years has been changing the world to suit his own purposes.
5. Man has been changing the world SINCE ancient times.
6. Our team has been doing plasma research FOR three years.
7. He has been investigating the cell properties SINCE he joined this laboratory.
8. I have been working at the effects of low temperatures on seeds FOR half a year.
9. We have been studying the theory of chromosome hereditary DURING last two years.
10. I have been gathering these data SINCE last winter.
9-b
10-b
11-c
12-d
13-b
14-a
15-b
16-c
17-b
18-b
19-a
20-c
21-b
22-e
Может am is are?
если да то
I am reading interesting book now.
I am writing an article.
He is kicking a ball.
She is cooking in the citchen.
We are catching butterflies.
They are shouting very loud.