用所给动词的适当形式填空。 1. I saw the boy ________ (play) football when I looked out of the window. 2. It’s important ________ (not give) goldfish too much food. 3. Children shouldn't spend too much time ________ (watch) TV. 4. Are they busy ________ (count) the birds? 5. My parent _________ (clean) the house at eight yesterday evening. 6. Look! The children _________ (plant) flowers. 7. If anybody _________ (break) the model plane, he ________ (have) to pay for it. 8. Suzy, _________ (not be) late for school. 9. Tom _________ (begin) to learn Chinese last year.