用括号内所给动词的适当形式填空。

1. If we don’t protect the wetlands, there ________ (be) no chance for us to see these endangered animals in the future.

2. So far, China _______ (develop) about 1360 kinds of green food.

3. In 1946, UNICEF _________ (set) up to help children whose lives were changed because of the Second World War.

4. He watched the result of the test and then _______ (draw) a conclusion.

5. Playing computer games is delightful, but _______ (spend) too much time on it may do harm.

6. By the time she was fifteen, Kitty _______ (teach) herself a foreign language.

7. Britain was the first country in the world _______ (have) a free health system.

8. Mr Liu’s daughter _______ (practise) the piano in Room 301 at 7.30 p.m. yesterday.

9. It was raining hard, but none of them said they ________ (stop) working in the fields.

10. Boats float in the direction of wind if they _______ (not control).