问题 选择题

哮喘是常见的呼吸系统疾病,严重的会导致肺泡的弹性回缩减弱,直接影响(  )

A.肺与外界的气体交换

B.血液与组织细胞的气体交换

C.气体在血液中的运输

D.胸廓的扩张与回缩

答案

呼吸道包括鼻腔、咽、喉、气管、支气管,哮喘一般是由于吸入了过敏性物质引起的支气管感染,症状有咳嗽、喘息、呼吸困难、胸闷、咳痰等.典型的表现是发作性伴有哮鸣音的呼气性呼吸困难.严重者可被迫采取坐位或呈端坐呼吸,干咳或咯大量白色泡沫痰,甚至出现紫绀等.

人体的气体交换包括体内的气体交换和肺与外界的气体交换,肺与外界的气体交换是通过呼吸作用完成的.吸气时,肋间肌收缩,肋骨上体,胸骨向上向外移动,胸廓的左右径和前后径变大,这时膈肌收缩,膈顶部下降,胸廓的上下径变大,这时肺内压小于外界大气压,外界的气体进入肺,完成吸气动作;呼气时正好相反.

哮喘是常见的呼吸系统疾病,严重的会导致肺泡的弹性回缩减弱,因此影响了肺泡的收缩扩张功能,使肺内气压变化较小,故影响了肺的通气,即肺与外界的气体交换.

故选A

阅读理解

阅读理解。

     The human body is a living machine, and, like all machines, it needs "fuel" (燃料) to supply it with energy.

This is provided by the food we eat. But how much do we need to stay healthy?

     The energy value of food is usually measured in calories. A calorie is the amount of heat required to raise

the temperature of 1 kg of water by 1℃. The number of calories people need per day is different. Also, the

number of calories you use at any one moment normally depends on the activity you are in.For example, you

need more calories for standing than for sitting, more for running than for walking, and so on.

     The energy in food is in the form of three kinds of chemical materials-carbohydrate (碳水化合物), protein

(蛋白质) and fat. Carbohydrate provides 3.8 Cal/gm, protein 4.0 Cal/gm, and fat 8.8 Cal/gm. Each food

contains different amount of these materials, as the round pictures show. 

                                       

1. The amount of calories supplied by equal amounts of milk, rice, and peanuts is the largest in the case of

    _____.

A. milk

B. rice

C. peanuts

D. rice or peanuts

2. Choose one statement from among A-D that agrees with the passage and the pictures above.

A. You need more calories for swimming than for mountain climbing.

B. Food contains energy in the form of carbohydrates, proteins and fuel.

C. Different people need different amounts of energy depending on their age, sex and the activities they are in.

D. 3 grams of milk provides 16.6 calories because carbohydrate provides 3.8 Cal/gm, protein 4.0 Cal/gm and

     fat 8.8 Cal/gm.

3. This article mainly tells us _____.

A. all the energy is in food

B. the human body needs energy

C. the number of calories depends on your activity

D. we must only eat peanuts to get calories

单项选择题