根据句意，用括号中所给词的适当形式填空。

1. Computers are used by people for ______ problems. (do)

2. Spaceship ______ people have reached other parts of the universe. (with)

3. Britain is only 30 kilometers away from ______. (French)

4. I think English is ______ than maths. (important)

5. The Great Wall is over six ______ kilometers long. (thousand)

6. The hat was ______ of silk. (make)

7. The moon ______ round the earth. (travel)

8. Sheep are ______ by farmers for producing wool and meat. (keep)