问题 单项选择题

双级齿轮式主减速器由()组成。

A.一对螺旋锥齿轮和一对圆柱齿轮

B.一对圆柱齿轮和一对斜齿圆柱齿轮

C.一对螺旋齿轮和一对斜齿锥齿轮

D.一对螺旋锥齿轮和一对斜齿圆柱齿轮

答案

参考答案:D

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     While watching the Olympics the other night, I came across an unbelievable sight. It was not a gold

medal, or a world record broken, but a show of courage.

     The event was swimming and started with only three men on the blocks. For one reason or another,

two of them false started, so they were disqualified. That left only one to complete. It would have been

difficult enough, not having anyone to race against, even though the time on the clock is important.

     I watched the man dive off the block and knew right away that something was worng. I'm not an

expert swimmer, but I can tell a good dive from a poor one, and this was not exactly medal quality.

When he resurfaced, it was evident that the man was not out for gold-his arms were waving in an

attempt at freestyle. The crowd started to laugh. Clearly this man was not a medal competitior.

     I listened to the crowd begin to laugh at this poor man who was clearly having a hard time. Finally he

made his turn to start back.It was pitiful. He made a few desperate strokes and you could tell he was

worn out.

     But in those few awful strokes, the crowd had changed.

     No longer were they laughing, but beginning to cheer. Some even began to stand and shout "Come

on, you can do it!" and he did.

     A clear minute past the average swimmer, this young man finally finished his race. The crowd went

wild. You would have thought that he had won the gold, and he should have. Even though he recorded

one of the slowest times in Olympic history, this man gave more heart than any of the other competitors.

     Just a short year ago, he had never even swum, let alone race. His country had been invited to

Sydney.

     In a competition where athletes remove their silver medals feeling they have somehow been cheated

out of gold, or when they act so proudly in front of their competitors, it_is_nice_to_watch_an_underdog.

1. From the passage we can learn that the young man ______.

A. made his turn to start back pitifully

B. was skillful in freestyle in the game

C. swam faster than the average swimmer

D. was not capable enough to win the medal

2. The crowd changed their attitudes because ________.

A. they felt sorry for the young man

B. they were moved by the young man

C. they wanted to show their sympathy

D. they meant to please the young man

3. According to the passage, "it_is_nice_to_watch_an_underdog" probably means ________.

A. it's amusing to watch a man with awful swimming skills

B. it's amazing to watch an ordinary man challenging himself

C. it's cheerful for athletes to act proudly before their competitors

D. it's brave enough for some athletes to remove the silver medals

4. What's the best title for the passage?

A. Compete for Gold!  

B. Try again!

C. Break a Record!  

D. Go for it!