问题 填空题

某班有55人,现根据学生的学号,用系统抽样的方法,抽取一个容量为5的样本,已知3号、25号、47号同学在样本中,那么样本中还有两个同学的学号分别为 ______和 ______.

答案

样本编号的间隔为11,

即相邻的2个编号相差11,已知3号、25号、47号同学在样本中,

∴还有两个同学的学号分别为3+11=14,25+11=36,

故答案为  14和36.

阅读理解

阅读理解。

     The Internet has become part of teenage life. A new report on 3,375 students aged from 10 to 18 in

seven Chinese cities found that 38 percent of them believe they use the Internet often.

     While most of them get useful information and use the Internet to help in their studies, some are not

using it in a good way. Many are playing online games too much.. A few even visit websites they shouldn't

look at. Hong Ying, a teacher from Beijing Yinghua Middle School warns that bad things can happen if young

people spend too much time on the Internet. She had a student who used to be good at school. But then he

started visiting sex websites. He went mad, cheated a girl and was taken away by the police.

     In order to help young people use the Internet in a good way, a textbook on good Internet behavior has

started to be used in some Shanghai middle schools this term.

     The book uses real examples to teach students all about good ways of using the Internet. The book gives

useful advice such as it's good to read news or to find helpful information to study. Teachers and parents all

think the book is a very good idea.

     Hong said the book will be a guide for teens using the Internet. She believes it will keep students away

from bad websites.

判断正误。

( ) 1. About 1282 among the 3375 students believe they use the Internet very often.

( ) 2. Not all children are using the computer in a good way. 

3. 将文中划线句子翻译成汉语。

    ______________________________________________________________________

4. What's the textbook about? 

    ______________________________________________________________________

5. What's the aim of the book? 

    ______________________________________________________________________

阅读理解与欣赏