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)
