Chia động từ: (Market) ..............................is a very inexact science

1. (Market) ..............................is a very inexact science.
2. I prefer (watch) .............................. film to (listen) .............................. to music.
3. The weather was too bad for us (go)...............................camping.
4. How about (play) .............................. soccer in the school yard?
5. It is dangerous (swim)................................in the deep river.
6. Instead of (feel) .............................. sorry for yourself, do some work for charity.
7. You are too young (understand)................................what is happening.
8. His plan is (keep)........................the affair secret.
9. I am looking forward to (receive) .............................. your letter.
10. The water was not warm enough for me (drink)………………………….