练习题　
1.__________________ (直到失去健康) that people know the value of health.

2. The bag was stuffed____________________( 脏衣服)

3.___________________ (很多朋友不在)， we decided to put the meeting off.

4._______________________ (给我印象最深的) were her liveliness and sense of humor.

5. There engines are___________________ (不如我们制造的那些发动机功率大) .

参考答案　

1. It is not until they lose it

2. with dirty clothes

3. With many friends absent

4. What impressed me the most

5. less powerful than the ones we have made