用所给词的适当形式填空。
1. He is __________ (please) with his brother's performance in the school sports meeting.
2. Water __________ (pollute) is really serious because the poison is bad for the river.
3. She __________ (have) her supper with her parents when I got to her home.
4. When he knew the dog died, he left __________ (happy) without a word.
5. We can use knives __________ (cut) meat when we are doing some cooking.
6. He didn't believe their words, so he decided to have a look _________ (he).
7. Please take buses, cars and __________ (taxi) to travel from one place to another.
8. Whom __________ they __________ (study) with this time yesterday?
9. Grandma _________ (have) a bad cold since last Saturday.
10. If we don't protect the wetlands, it will be __________ (possible) to see these birds in the future.
