问题 问答题 简答题

机械密封动环和静环之间是如何实现密封的?

答案

参考答案:

动环和静环间相对贴合旋转的密封,是动密封,是依靠弹簧加荷装置和介质压力,使动环和静环的接触面上产生一个合适的压紧力,是这两个光洁、平直的端面紧密贴合,端面间维持一层极薄的流体膜来达到密封的目的。

改错题

短文改错(共10小题,每小题1分,满分10分)       

此题要求改正所给短文中的错误。对标有题号的每一行做出判断:如无错误,在该行右边横线上画一个勾(√);如有错误(每行只有一个错误),则按下列情况改正:

此行多一个词:把多余的词用斜线(\)划掉,在该行右边横线上写出该词,并也用斜线划掉。

此行缺一个词:在缺词处加一个漏字符号(∧),在该行右边横线上写出该加的词。

此行错一个词:在错的词下划一横线,在该行右边横线上写出改正后的词。

注意:原行没有错的不要改。 

I had to stay later at the hospital that night to         76.                

do an operation. I finally 1eft about 11 p.m. I                   77.                

drove to home slowly because the weather was                 78.                

terrible -- a strong wind was blown and it was                  79.                

raining heavy. I was turning into our road when                80.                

a man suddenly run in front of my car. I almost                81.                

hit him but he stopped just in time. I was very                  82.                

frightened and the man looked frightened too. I                83.                

got out of the car, but he ran away after I could                84.                

ask him if he was right. It was very strange.                      85.                

单项选择题