下列关于网络的叙述中，错误的是A．网络协议主要由语法、语义和时序组成 B．语法规定了

我国分业监管体制正式形成的标志是【 】

A．证监会的成立

B．保监会的成立

C．银监会的成立

D．中央银行的成立

老年性皮质性白内障按其发展过程分为4期：______、______、______、______。

阅读理解。

     Mr. Andrews was waiting for a subway train in the city. The train pulled into the station and stopped.

As Andrews was getting ready to board the train, he saw an elderly blind man fall to the tracks (站台).

David Schnair, aged 75, had mistaken the space between two subway cars for a door, while feeling his

way with a cane. Instead of ending up inside the train, Schnair fell off the platform and landed under the

train.

     Andrews jumped down to the tracks to save Schnair. He pulled the man to safety. Onlookers immediately

declared Andrews a hero. Messages began to pour in from all over the country. Some people sent checks.

The largest was for $3,000. President called Andrews and wished him a Merry Christmas and a good new

year.

     Andrews had been on the subway because he was returning from a job interview. He probably would

have been hired anyway, but all the good publicity (宣传) made it a sure thing.

     After about a week of newspaper stories and donations of food, money and gifts for his children, Andrews

faded from limelight. Most people assumed that the story had come to a happy ending, but it didn't quite

happen that way. Andrews did start his new job, but the company moved to New Jersey. Andrews didn't

have any way to get to work, so he had to give up. It wasn't long before he was back to job hunting and

being discouraged again. Few newspapers, however, bothered to tell their readers what happened to Mr.

Andrews after he became a hero.

1. Schnair fell off the platform because _____. [ ]

A. onlookers pushed him down

B. he was walking carelessly

C. he thought he was at a door

D. the train got to the station fast

2. What does the underlined sentence mean in Paragraph 4? [ ]

A. Andrews disappeared from the public attention.

B. Andrews lost his job for his fame.

C. Andrews gained his popularity with the public.

D. Andrews lost his interest in newspaper.

3. It can be inferred from the passage that _____. [ ]

A. it was not wise for Andrews to give up his job

B. the public didn't show enough kindness to Andrews

C. the newspapers paid little attention to Andrews' life

D. life is difficult for the unemployed

检验镗孔精度时应消除哪些误差？

衡量中国后发优势可以比较中国的（）与发达国家的差距。

A.国内生产总值

B.国家税收总量

C.人均收入水平

D.人均可支配收入