Part 2. correct the mistakes 1.what are you doing when the police arrived? 2. mary can"t answer the questions.she hadn"t read the text yet. 3. it is often snow in december. 4. the lesson started since twenty minutes ago. 5. these pupils have finished unit fifteen last week. 6. they have been written the test for an hour. 7. john is doing exercises since 8 o"clock. 8. the boy are not runing right now.they are playing tennis. 9. i am thinking he will be happy to get the toy. 10. he was writing a new book for four years, but he has done only half of it.

1. What were you doing when the police arrived?
2. Mary can't answer the questions. She hasn't read the text yet.
3. It often snows in December.
4. The lesson started twenty minutes ago.
5. These pupils finished Unit Fifteen last week.
6. They have been writing the test for an hour.
7. John has been doing exercises since 8 o'clock.
8. The boy is not running right now. He is playing tennis.
9. I think he will be happy to get the toy.
10. He has been writing a new book for four years, but he has done only a half of it.