问题 多项选择题

关于OTUk帧加扰的说法,正确的有?()

A.加扰的目的是为了避免长0和长1的情况,保证设备能从业务中提取时钟

B.加扰是在FEC编码前进行的,即FEC字节不进行加扰操作

C.加扰和解扰的算法完全一样,加扰后的信号再进行次加扰算法即相当于解扰

D.收端先进行FEC解码,再进行解扰

答案

参考答案:A, C

阅读理解

My grandfather is eighty years old now. He always complains about how fast things have changed, and he often says that life used to be better.

Families aren’t families they used to be. A lot of families have broken up. If husband and wife have problems with their marriage, they no longer stay together. And mothers used to stay at home and take care of their children, but now not any more. Everyone is busy working. Mother used to spend all day cooking in the kitchen. But now the family don’t eat home-cooked food any more.

And the cars! No one walks any more. More and more people drive. Students used to walk 5 miles to school every day, even in winter. But nowadays students don’t. And in school, children don’t have to think any more.. In math class, for example, they used to add, subtract, multiply and divide(加减乘除)in their heads. Instead, they use calculators.

And people today have TV and computers, and they don’t talk to each other any more. They are too busy to talk, too busy to eat, too busy to think.

Life used to be simple, but it isn’t any more.

小题1:What does my grandfather think of the life now?

A.He thinks the life now is very good.

B.He thinks the life now is worse than it used to be.

C.He thinks the life now is better than it used to be.

D.He thinks the life is the same as it used to be.小题2:What does the underlined word “marriage” mean in Chinese?

A.生活

B.工作

C.婚姻

D.家庭小题3:What has happened these years according to the passage?

A.Children don’t have to think any more in school.

B.Students use calculators in math class.

C.Some used to walk to school, but now they don’t.

D.All of above.小题4:What changes have happened to some families?

a. People have TV.  

b. People like to eat home-cooked food.

c. Lots of families have computers.

d. Lots of couples(夫妇)live apart because of unhappy problems.

A.a, b, d

B.b, c, d

C.a, b, c

D.a, c, d小题5:Which is TRUE according to the passage?

A.Life now is much simpler.

B.People have too much time to talk with each other now.

C.The writer’s grandfather only complains and pays no attention to better life now.

D.Lots of mothers stay at home and look after their children.

单项选择题