问题 选择题

如图是某人在一次平静呼吸过程中肺内气压的变化曲线.下列有关叙述中,不正确的是(  )

A.在AB段,膈肌收缩,胸廓的上下径增大

B.在AB段,肋骨间的肌肉收缩,胸廓横向扩张

C.在BC段,膈肌舒张,膈的面积缩小

D.在BC段,肋骨间的肌肉舒张,胸腔的容积缩小

答案

呼吸运动是指人体胸廓有节律的扩大和缩小的运动,包括吸气过程和呼气过程,呼吸运动主要与肋间肌和膈肌的运动有关.

曲线图中,AB段表明肺内气压低于外界大气压,是吸气时肺内气压的变化,人在平静状态下,肋间肌收缩时,肋骨向上向外运动,使胸廓的前后径和左右径都增大,同时膈肌收缩,膈的面积缩小,膈顶部下降,使胸廓的上下径都增大这样胸廓的容积就增大,肺也随着扩张,外界空气通过呼吸道进入肺,完成吸气的过程.

曲线图中,BC段表明肺内气压高于外界大气压,是呼气时肺内气压的变化,当肋间肌舒张时,肋骨因重力回落向下运动,使胸廓的前后径和左右径都变小,同时膈肌舒张,膈的面积增大,膈顶部上升,使胸廓的上下径变小,这样胸廓的容积就变小,肺也随之回缩,肺内气压高于外界大气压,肺内气体通过呼吸道排出体外,完成呼气.因此在BC段,膈肌舒张,膈的面积增大不是缩小,可见C符合题意.

故选C

阅读理解

As we get older, most of us worry about grey hair, wrinkles and maintaining a youthful body. But people often don’t realize the voice needs looking after. Here, Mr. Rubin, a voice expert, reveals how to keep your voice youthful.

Drink more fluid and avoid spicy food

You need water for the vocal cords(声带) to vibrate(振动) well. The body must be kept hydrated enough to make the vocal cords operate well. Drinking 1.5 liters of water a day at intervals of 15 minutes is very important. Mr. Rubin advises avoiding foods with an annoying effect on the stomach, such as onions, chili, fizzy drinks and chocolate.

Rest the throat and talk regularly

The vocal cords can be scared if you use your voice during a bad cough. If you have a case of laryngitis(喉炎) with a cold, you should rest your voice for a day or two, and seek medical advice.

Simply staying sociable and using your voice is very important. “As older people get less mobile, they can become socially isolated and speak less.” says Mr. Rubin. “The elderly need to communicate with people more. By using the vocal cords, they enable the ageing process to slow down. ”

Improve your posture

Good posture is essential to keeping the voice young, so we’d better stand properly. Exercise helps you take deeper breaths as it means there is better airflow through the voice box, producing a stronger tone.

Sing in the shower

This is one of the best ways to preserve your voice, as it keeps the larynx muscles strong while the steam lubricates(使润滑) the voice box. “Singing is gymnastics for the voice,” says Mr. Rubin. Joining a choir is one of the best ways to preserve a youthful tone.

小题1:Mr. Rubin gives us advice on ________.

A.ways to keep us from aging

B.ways to talk with other people

C.ways to keep our voice youthful

D.prevention of diseases caused by talking too much小题2:Which of the following statements is TRUE in the opinion of Mr. Rubin?

A.We should stand properly to keep our voice youthful.

B.Professional singers’ voices tend to age quickly.

C.The steam can do great harm to the voice.

D.Taking more onions can keep us healthy.小题3:To protect the voice, the old people should       .

A.get less mobile

B.communicate with others more

C.avoid using the voice

D.lie in bed more小题4:What can we learn from the text?

A.Most people have realized the importance of protecting voice.

B.It’s hard to keep the vocal cords strong through exercise.

C.Singing in the shower is among the best ways to keep our voice youthful.

D.Shouting now and then benefits our vocal cords.

判断题