问题 填空题

17世纪前,人们认为五光十色的世界中太阳光是最纯的,真的如此吗?让一道白光通过三棱镜,结果在光屏上自上而下出现了红、橙、黄、绿、蓝、靛、紫的色带,我们把这个现象叫做光的______,人们发现将______三种颜色的光按不同比例混合可以得到各种颜色的光,因此称这三种色光为光的三原色.人们还发现,色散光带红光外侧有一种不可见光叫做______,它的典型特点是能使物体______;紫光外侧有一种不可见光叫做______,它的典型特点具有______效应,利用这一特点可以进行人民币防伪.

答案

当太阳光经过三棱镜后,由于棱镜对不同色光的偏折程度不同,会分解成红、橙、黄、绿、蓝、靛、紫七种单色光,这是光的色散现象.

红光、绿光、蓝光叫做三原色光.人们发现将红光、绿光、蓝光三种颜色的光按不同比例混合可以得到各种颜色的光,

在红光之外有看不见的红外线,红外线的热效应很强,太阳光向地球辐射热,主要依靠红外线.

在紫光之外有看不见的紫外线,紫外线可以使荧光物质发光,所以可以用来做验钞机.

故答案为:色散;红光、绿光、蓝光;红外线;发热;紫外线;荧光.

阅读理解

任务型阅读:阅读下面的短文,并根据短文后的要求答题。

    Our local Community (社区) Youth Club is a very popular organization with young people in my town. I

have been a member for four years now and I've taken part in a lot of interesting projects. There include fun

activities such as holiday camps and discos.We have even made a video. 

    But it isn't all just enjoyment. We have also started doing social work to help people in our neighborhood.

We have organized activities for small children during the holidays. We have also formed a special support

group to help young people stop smoking. We are particularly proud of the most recent group we have created.

It organizes regular visits to the local home for the elderly. This idea came from a school visit to a old people's

home several days ago. My class spent an afternoon at the home and everyone found the visit very rewarding.

(有意义的)

    The old people at the home were excited. They were very talkative (健谈的) and they told us their personal

stories. During our visit, the home was full of the sound of laughing. We sang songs and played games with

the old people and bad tea together. But we realized that life wasn't always easy. Some of them were in poor

health and were very unhappy. They couldn't go outside and the children's visits brought some into their lives.

     Many young people like me have very little contact with elderly people.As a result, we have a lot of wrong

ideas about them. We have little or no idea of the kind of lives they lead in the homes. after this visit, my friends

and I decided we should do something to help improve the quality of their lives.

     Since the creation of our visiting group, over twenty volunteers have joined us. Up to now, we have

organized three evening parties and the most important. Club members regularly visit old people and everyone

finds the experience rich and rewarding.

(1:判断正误 2:翻译成汉语 3-5:简短回答问题)

1. The writer is a member of the Youth Club. (      )

2. They couldn't go outside and the children's visits brought some into their lives

    _____________________________________________________________________________

3. How did the old people in the home feel when the young people visited them?  

    _____________________________________________________________________________

4. What did the writer and his friends decide to do after the visit to the home for the elderly?

    _____________________________________________________________________________

5. Why do young people have wrong ideas about the elderly?

    _____________________________________________________________________________

单项选择题