问题 单项选择题

如果对数据的实时性要求比较高,但对数据的准确性要求相对较低(如在线电影),一般可在传输层采用______协议。

A.UDP

B.TCP

C.FTP

D.IP

答案

参考答案:A

解析:[知识点] TCP/IP协议[评析] UDP协议是一种单工的、面向无连接的、不可靠的传输层协议。由于不需要连接,其实时性要高于 TCP协议,但可靠性较差,一般可以用来传输实时性强,但准确性要求不高的场合。TCP协议与UDP相反,一般用在准确性要求较高的场合。FTP为文件传输协议,其为应用层协议。IP为网络层协议,用来实现不同子网间的互联。

阅读理解

阅读理解。

     An old woman from the United States is helping develop a small Chinese village. She lived there when

she was a child.

     In the early 20th century, Eunice Moe Brokck's parents came to Shandong Province and they gave birth

to her there. As she grew up, Brock saw the poverty (贫困), illness and war in China. So when she left China

at the age of 13, she decided to come back to help the poor people there.

     After her husband died, the old woman sold her house, her car, her forest and other things and moved to

China in 1999. She lived in Liumiao Village in Liaocheng of Shandong Province to help the villagers there.

     Though she is now in her nineties, she is still busy helping them. In the past few years Brock built a

computer room for the village school with her own money, and bought desks, chairs and books for students.

She also has been trying to improve the medical care conditions in a number of villages. In Liumiao, every

child can play with toys in Brock's home. At Christmas she always buys a lot of candies and takes them to

schools for students.  

     "I'm an American, but I love China," she said.

1. Eunice Moe Brock was born _________.

A. in Shandong Province

B. in the United States

C. in the south of China

2. Brock returned to China _________ years ago.

A. nine

B. thirteen

C. twenty

3. From the passage we know that Brock is _________.

A. less than 90 years old

B. over 90 years old

C. a middle-aged woman

4. Which of the following is true?

A. Brock's husband died while she was in China.

B. The villagers got much money from Brock.

C. Brock has made a great contribution to the villages in China.

5. The best title for the passage is _________.

A. A Woman in China

B. A Poor Village in China

C. An American Woman with a Chinese Heart

多项选择题