问题 选择题

要了解一批日光灯灯管的使用寿命,从中抽取了40个灯管进行实验。在这个问题中,40个灯管的使用寿命是

A.总体

B.个体

C.样本容量

D.总体的一个样本

答案

答案:D

分析:本题考查的是确定总体。解此类题需要注意“考查对象实际应是表示事物某一特征的数据,而非考查的事物”。我们在区分总体、个体、样本、样本容量这四个概念时,首先找出考查的对象,从而找出总体、个体,再根据被收集数据的这一部分对象找出样本,最后再根据样本确定出样本容量。

解答:本题中的总体是指这批日光灯管的全体的使用寿命,个体是指每只日光灯管的使用寿命,样本是指从中抽取的40只日光灯管的使用寿命,根据抽样调查的特征可知,40个灯管的使用寿命是总体的一个样本,故选D。

点评:本题考查的是确定总体、个体、样本。解此类题需要注意“考查对象实际应是表示事物某一特征的数据,而非考查的事物”。

阅读理解

阅读理解。

    If you don't use your arms or your legs for some time, they will become weak; when you start using them

again, they will gradually (逐渐地) become stronger again. Everybody knows this. Yet many people do not

seem to know that it is the same with our memory.   

    If a friend says that his arms and legs are weak, we know that it is his own fault. But if he tells us that he

has a poor memory, many of us think that his parents are to blame (责怪), and few of us know that it is just

his own fault.   

    Have you ever found that some people can't read or write but they usually have better memories? This is

because they can not read or write and they have to remember things; they can not write them down in a little

notebook. They must remember dates, names, songs and stories; so their memories are being exercised the

whole time.   

    So if you want a good memory, learn from these people: practice remembering.

1. What will happen to your arms or legs if you don't use them for some time?

    They will be ______.  [ ]

A. strong

B. broken

C. weak

D. hurt

2. What does the word "fault" mean in the second paragraph? [ ]

A. 困难

B. 过错

C. 粗心

D. 聪明

3. What do many of us think of the person with a poor memory? [ ]

A. His parents are to blame.

B. He isn't clever.

C. He is foolish.

D. His parents are very clever.

4. Why do some people usually have better memories but they can't read or write?

    Because ______. [ ]

A. they are stronger

B. they often practice remembering things

C. they have strong arms and legs

D. their parents are good

5. What does the passage mainly (主要) talk about? [ ]

A. Arms.

B. Legs.

C. Behaviors.

D. Memories.

名词解释