问题 单项选择题

HFC应用 (22) 传输技术,综合接入多种业务。HFC的用户端从PC机接收的以太帧被封装在时隙中,经过 (23) 调制后,通过HFC网络的上行数据通路传送给CMTS。

23()

A.QAM

B.BPSK

C.QPSK

D.DQPSK

答案

参考答案:C

解析:

HFC综合应用了模拟和数字的传输技术,在传输过程中利用的是QPSK即四相调制技术。

阅读理解

阅读短文,选择正确答案。

    You speak, write a letter, and make a telephone call. Your words carry a message. People communicate

(交流) with words. Do you think you can communicate without words? A smile on your face shows you are

happy or friendly. Tear in your eyes tell others that you are sad. When you put up your hands in class, the

teacher knows you want to say something or ask questions. You shake your head, and people knows you are

saying "No". You NOD and people know you are saying "Yes". Other things can also carry messages. For

example, a sign at the bus stop helps you to know which bus to take. Signs on doors tell you where to go in or

out. Have you ever noticed that a lot of signs around you and that you receive messages from them all the time?

People can communicate in many other ways. An artist can use his drawings to tell about beautiful mountains,

about the blue sea and many other things. Books are written to tell you about all the wonderful things in the

world and also about people and their ideas. Books, magazines, TV and radios and films all help us to

communicate with each other. They all help us to know what is going on in the word and what other people are

thinking about.

1. Which of the following is TRUE? [ ]

A. We can't communicate with each other without words.

B. We can communicate in many different ways.

C. We can't communicate with body language.

D. It's very difficult to receive messages from signs.

2. The word "NOD" means _____ in Chinese according to the context. [ ]

A. 点头

B. 摇头

C. 弯腰

D. 挥手

3. When we see somebody smile, then, he must be feeling ______. [ ]

A. angry

B. pleased

C. surprised

D. sad

4. We can learn news from            . [ ]

A. newspapers

B. radios

C. TV

D. A, B and C

5. A sign at the bus stop tells you _____. [ ]

A. how many buses there are

B. what kind of bus it is

C. where the bus comes and goes

D. how much money you'll pay for the ticket

选择题