句型转换。

1. The doctor asked the old man to stop smoking. (改为一般疑问句)

    ________ the doctor ________  the old man to stop smoking?

2. The girl is clever. She can work out difficult problems. (合并为一句)

    It is clever ________  the girl ________ work out difficult problems.

3. I prefer doing everything for myself to asking my mother for help. (保持句意基本不变)

    I would ________  do everything for myself ________  ask my mother for help.

4. Those local businesses supported the charity show. (改为被动语态)

    The charity show ________  ________  by those local businesses.

5. Martin was so excited at the news that he couldn't fall asleep. (改为简单句)

    Martin was ________  excited at the news ________  fall asleep.

下列物质可用于自来水厂原水的消毒，但又不会造成环境污染的是

A．液氯

B．臭氧

C．酒精

D．醋酸