依据现行《建筑设计防火规范》的规定，有一高层工业建筑，层高为5m，其水枪的充实水柱至

简单介绍链斗输送机结构及特点？

异型接头的联结应使两钢轨工作面轨距线与（）水平线都相吻合。

A.轨顶最高点

B.轨底最底点

C.轨顶

D.轨顶轨底的中部

阅读理解。

     After twenty years of shaving himself every morning, a man in a small Southern town thought he had

enough. He told his wife that he wanted to let the barber shave him every day. He put on his hat and coat

and went to the barber shop.

    The barber's wife Grace was working that day, so she performed the task. Grace shaved him and said,

"That will be $20." The man was surprised, but he paid the bill and went to work.

    The next morning, the man looked in the mirror and his face was as smooth as it had been when he left

the barber shop the day before. "Not bad," he thought. "At least I don't need to get a shave every day."

    The next morning, the man's face was still smooth! Two weeks later, the man was still unable to find

any trace of whiskers on his face. It was more than he could take and he was frightened, so he returned

to the barber shop.

     "I thought $20 was too high for a shave, but now I think $20 is too little," he told the barber's wife.

"You must have done a good job. It's been two weeks and my whiskers still haven't started growing back."

The expression on her face didn't even change, and she said, "You were shaved by Grace. Once shaved,

always shaved."

1. It is implied in the first sentence of the passage that ______. [ ]

A. the man lived a very poor life

B. the man liked shaving himself

C. the man finally got bored of shaving himself

D. the man decided not to shave again

2. We learn that at first the man thought $20 for a shave was ______. [ ]

A. too little

B. too much

C. proper

D. impossible

3. What can we learn from the passage? [ ]

A. Everybody in the town knows Grace.

B. Nobody wants to be shaved by Grace in the town.

C. The man's whiskers grew back at last.

D. The man was scared by the resulted two weeks later.

下列句中破折号用法不同的一项是(　　)

A．哦。——老爷没有事了？

B．嗯，——我们想把她的坟墓修一修。

C．我是你的——你打的这个人的妈。

D．鲁大海，你现在没有资格跟我说话——矿上已经把你开除了。

为保证安全飞行，在飞行过程中，至少需要花（）的时间进行搜索。

A.50%

B.70%

C.90%