根据下列句子的意思及所给的汉语提示，写出空缺处单词、固定短语或固定搭配的

正确形式。

1. People should be p______ from polluting the environment.

2. Could you write a ______ (describe) of your mother?

3. I think it is ______ (danger) for children to be close to wild animals.

4. Can you type and talk ______ (同时)?

5. Cathy was ill. So I went on business ______ (代替) her.

同一台发动机必须选用同一厂牌活塞的原因是要保证（）。

A.相同修理尺寸

B.相同组别

C.相同的尺寸和形位误差

D.相同的膨胀系数