问题 多项选择题

关于数字证书的原理说法错误的是()

A.数字证书采用公钥体制,即利用一对互相匹配的密钥进行加密、解密

B.每个用户自己设定一把公有密钥,用它进行解密和签名

C.当发送一份保密文件时,发送方使用接收方的私钥对数据加密,而接收方则使用自己的私钥解密

D.设定一把公共密钥为一组用户所共享,用于加密和验证签名

答案

参考答案:B, C

阅读理解

阅读理解。

     Today we find that school students hardly spend much time on sports. Is it because they aren't interested in sports? No, they often say they have other more important things to do.

     What are these important things? Examinations! They have to spend much time on all kinds of examinations at school. So many of them almost become bookworms(书呆子). Books stop them from going out for sports. Because of the pressure from their parents and teachers, the students have to work harder and spend most of their time on books. As for the students, they want to get good results so that they can improve their studies. So it is necessary for them to give all of their free time to their studies and stop their school sports.

     In fact, education(教育) can't go without physical(身体的) exercises, because a quick mind hardly goes along with a weak body. If you don't have a strong (强壮的)body, you can never get anything or any great success in your life.

1. Because of _______, the school students can't spend much time on sports.  

A. no interest      

B. examinations  

C. education

2. The word "pressure" means _______

A. 幸福    

B. 压力    

C. 好办法

3. If you don't have a _______  , you can never get anything. 

A. good father    

B. strong body    

C. weak body

4. The writer means the students should _______. 

A. work all day and all night          

B. not play sports

C. have all kinds of sports after studying

5. Which of the following is wrong? 

A. The students don't go out for sports because of their parents.

B. The students stop their school sports because they are busy with their studies and examinations.

C. Without a strong body one can't get a great success in life.

多项选择题