Use the pronouns "some, any, no" and their derivatives "somebody, anybody, nobody, something, anything, nothing".
1. There are .... apple-trees in the garden. 2. Has he ... money in his pocket? 3. I see ... in the dark room. 4. He had ..... in his hand. 5. Can .... solve this difficult problem on the computer? 6. Listen, ...... is knocking at the door. 7. Are there ... lectures in the evening?. 8. Ask ... else about it. 9. I must tell you .... very interesting. 10. I don't know .... about this man.

1. There are some apple-trees in the garden.

2. Has he any money in his pocket?

3. I see somebody/nobody in the dark room.

4. He had something/nothing in his hand.

5. Can anybidy solve this difficult problem on the computer?

6. Listen, somebody is knocking at the door.

7. Are there any lectures in the evening?.

8. Ask somebody else about it.

9. I must tell you something very interesting.

10. I don't know anybody about this man.