阅读文段,根据题目要求找出单词。

    Jack is a businessman. He has three friends. They are Mary, Ann and David. Jack has a car. He drives

to work. Mary works in a hotel. She goes to work on her bicycle. Where does Ann work? She works in

a supermarket. She is a clerk. She goes to work by bus. David works in a park, and the park is not far

from his home. How does he go to work? He walks to work.

    The four friends often have parties on weekends. 

表示职业的词:    1             2             

表示工作单位的词:3             4                5             

膈肌收缩时，胸腔的变化是（   ）

A 上下径增大 B 上下径缩小C 前后径增大D 前后径缩小