用括号中词语的正确形式填空。

1. It is ______ (polite) to leave without saying goodbye to the host.

2. These containers can be used again.  So they are called ______ (use) containers.

3. The doctor said the old man's condition was ______ (hope) because the operation was not successful.

4. Those small factories are causing a lot of ______ (environment) ______ (pollute) with all their noise

    and smoke.

5. The more exercise young students take, the more ______ (energy) they will become.

6. The ______ (nation) emblem (国徽)of England is a rose.

7. The lecture was ______ (agree) to Tom, so he fell asleep quickly.

8. Human beings are ______ (create) animals.  They have created a lot of wonders.