问题 选择题

读图,回答题。

小题1:图中所示近地面大气的热量主要来自( )

A.A

B.B

C.C

D.D小题2:从数量上看,A>B的原因是(  )

A.大气对A具有削弱作用

B.B大部分被大气吸收

C.A大部分被大气吸收

D.B大部分被地面吸收小题3:在图中,夜晚阴天比晴天气温高,是因为( )

A.辐射A减弱

B.B辐射增强

C.C辐射增强

D.D辐射增强

答案

小题1:C

小题2:A

小题3:D

题目分析:本题考查大气的受热过程及大气对地面保温作用。

小题1:大气逆辐射对地面起到保温作用。近地面大气吸热增温后,也向外进行辐射,叫大气辐射。大气辐射中一小部分向上,散失到宇宙空间;其余绝大部分是向下的,因其与地面辐射的方向相反,称为大气逆辐射。大气逆辐射使得大气把从地面辐射中获取的热量还给了地面,所以说图中D对地面起着保温作用。

小题2:大气对太阳辐射具有吸收、削弱、散射作用。所以从数量上看,A>B。

小题3: 大气对地面具有保温作用,地面辐射是对流层大气的主要直接热源。大气逆辐射使得大气把从地面辐射中获取的热量还给了地面,夜晚大气层把吸收的大量地面辐射的热量还给了地面。所以多云、阴天时的夜晚比晴天气温高。在图中,夜晚阴天比晴天气温高,是因为D辐射增强。

点评:本题难度适中,考查学生对所学知识的应用能力,对于本小题学生将大气的受热过程及大气对地面保温作用的知识图像化即可。

阅读理解

阅读理解。

     Your body, which has close relations with the food you eat, is the most important thing you

own, so it needs proper treatment and proper nourishment (营养).The old saying "An apple a

day keeps the doctor away "is not as silly as some people think. The body needs fruit and

vegetables because they contain vitamin C. Many people take extra vitamins in pill form,

believing that these will make them healthy.

     But a good diet is made up of nourishing food and this gives all the vitamins you need. The

body doesn't need or use extra vitamins, so why waste money on them?

     In the modern western world, many people are too busy to bother about eating properly.

They  throw anything into their stomachs, eating hurriedly and carelessly. The list of illnesses

caused or made worse by bad eating habits is frightening.

1. "Your body has close relations with the food you eat." It really means that ______.

A. all kinds of food you eat can be made into your body

B. your body is made up of the food you eat

C. what you eat has great effect on your health

D. the more you eat, the fitter you will feel

2. In the modern western countries ______.

A. people don't want to pay more attention to their eating

B. lots of people's illnesses are caused or made worse by bad eating habits

C. people throw everything into their stomachs without chewing

D. people are only too busy to cook meals for themselves

3. From the passage we can draw a conclusion that if we want to keep healthy, we should ______.

A. only eat an apple a day

B. eat properly

C. take as many vitamin pills as possible

D. throw something into our stomachs slowly and carefully

单项选择题