问题 单项选择题

OSI参考模型中实现路由选择功能的是()。

A.传输层

B.网络层

C.数据链路层

D.物理层

答案

参考答案:B

解析:

[分析]:本题考查计算机网络的基础知识。

在OSI的7层模型中,物理层的作用主要实现比特流的透明传输;数据链路层对物理层传递的比特流进行检测、成帧,主要实现错误检测、流量控制,将有差错的物理链路变为无差错的链路等功能:网络层主要为数据包计算和选择适当的路径,提供路由功能;传输层实现分组的端到端的无差错传输。

阅读理解

After death, John went to see God. God looked at him, feeling very unhappy, “You’ve lived in this world for 60 years. Why haven’t you gotten any result at all?” God asked.

John argued, “My God, I couldn’t become a successful person just because you didn’t give me any chance. If you let that magic apple hit on my head, the man who found the law of gravity should be me.”

God said, “OK, we might as well try again.”

God rocked his hands and the time turned back to a few hundred years ago.

God shook the apple tree for the first time, when a red apple fell and happened to drop on John’s head. John picked up the apple, wiped it and ate it up as soon as possible.

God allowed another bigger apple drop on John’s head and John ate it up once again.

God shook the apple tree for the third time, when a much bigger apple fell on John’s head. John got mad, picked up the apple, threw it out heavily. Then he shouted angrily: “The apple annoyed my sweet dream! What a bad luck!”

The apple flew out and happened to fall on Newton’s head. Newton awoke and picked up the apple. After a long time of thinking, he discovered the law of gravity at last.

The time returned once again now.

God said to John, “John, do you understand it now?”

John asked, “My God, please give me another chance…I will …”

God shook his head and said, “No. The chance that the apple drops on the head of everyone is the same, but each person’s ability to catch the chance is different.” 

小题1:When did John die?

A.At the age of 50.

B.At the age of 60.

C.At the age of 70.

D.At the age of 80.小题2:How many times was John hit by apples?

A.Once.

B.Twice.

C.Three times.

D.Four times.小题3: What did John do after he was hit by the apple for the second time?

A.He ate the apple at once.

B.He got angry and shouted.

C.He threw the apple out.

D.He thought something over.小题4: Which is the best title of the passage?

A.God’s Words

B.Annoying Apples

C.John’s Life

D.Lost Chances

单项选择题 A1/A2型题