用所给词的正确形式填空。

( talk, help, read, cost, keep, change, do, visit, go, sit)

1. ________ it ________ much to live here?

2. The teacher looked at the clean classroom and said we ________ a good job.

3. The Smiths ________ greatly in the last two years.

4. He heard her singing aloud in the next room, so he _____ in a louder voice.

5. It was said that some foreigners ________ our class the next week.

6. They have done what they can ________ us stop the sandstorm.

7. Why are there so many people over there? Let's go and see what ________ on.

8. My family ________ at table when the door bell rang.

9. It's very cold in the room. Let's make a fire ________ us warm.

10. What do you think ________ about at the meeting tomorrow?