问题 选择题

关于吸气过程的叙述,不正确的是(  )

A.肋间外肌收缩使肋骨上提并外展,胸骨上移,使胸廓横径增大

B.膈肌收缩,膈顶下降,使胸廓纵径加长

C.肋间外肌和膈肌舒张,使胸廓纵径缩短,胸廓横径缩短

D.胸廓扩大,肺容积扩张,肺内气压下降到低于大气压时吸气

答案

人体吸气时,肋骨间肌肉与膈肌收缩,引起胸腔前后、左右及上下径均增大,胸廓容积增大,胸腔扩大,肺随之扩大,造成肺内气压小于外界大气压,外界气体进入肺内,形成主动的吸气过程;肋骨间肌肉与膈肌舒张,引起胸腔前后、左右及上下径均减小,胸廓容积减小,胸腔缩小,肺被动回缩,造成肺内气压大于外界大气压,气体出肺,形成被动的呼气过程.
故选C.

阅读理解

阅读理解。

     The Chinese New Year is the most important festival for the Chinese people. For the Chinese, the New

Year comes with the first day of the First Moon, between January 21 and February 19. It takes about 15 days

to prepare for it.

     On the eve of the festival, people close the shops and the streets are empty. Everyone locks their doors and

stays at home.

     In the morning, people dress in their best clothes, and usually the old stay at home, and the young go out to

pay a New Year Call (拜年). It is an important time for the young. The young people bow (鞠躬) to the old

people. The Chinese call this"Ke Tou". This means"touching the ground with the forehead (额头)". Then the

young people give their best wishes to the old people. The old people give children gifts or lucky money.

     They are very polite and do not use bad words. It's the most important day of the year.

1. "The Chinese New Year" in the passage means"_____".

A. Mid-autumn Festival

B. the Spring Festival

C. Christmas Day

D. the Dragon Boat Festival

2. It takes about _____ to get ready for the Chinese New Year.

A. a few days

B. twelve days

C. half a month

D. three weeks

3. People don't open their shops _____ the festival.

A. on the first day of

B. on the night before

C. in the morning of

D. in the afternoon of

4. From this passage we can know that _____ give children gifts or lucky money.

A. the teachers

B. their friends

C. the old people

D. their brothers

5. On the Chinese New Year's Day, what do people usually say to each other when they meet?

A. Good luck.

B. Best wishes.

C. Good morning.

D. Both A and B.

选择题