1. I never ask him any questions.
2. Look! The teacher is drawing a picture on the blackboard.
3. When did you buy the cassette?
4. It's the best story I have ever read.
5. I have never seen so funny monkeys.
6. He enjoys playing the guitar.
7. I wrote the exercises an hour ago.
8. Who is using the telephone?
9. The sandwich is on the table, isn't it?
10. Jack has been to Rostov, hasn't he?