问题 名词解释

电动机的自起动

答案

参考答案:

厂用系统中正常运行的电动机,“当其供电母线电压突然消失或显著降低时,若经过短时间(一般在0.5—1.5s)在其转速末下降很多或尚未停转以前,厂用母线电压又恢复正常(如电源故障排除或备用电源自动投入),电动机就会自行加速,恢复到正常运行,这一过程称为电动机的自起动。

阅读理解

I recently turned fifty,which is young for a tree,midlife for an elephant,and ancient for a sportsman.Fifty is a nice number for the states in the US or for a national speed limit,but it is not a number that I was prepared to have hung on me.Fifty is supposed to be my father’s age,but now I am stuck with this number and everything it means.

A few days ago,a friend tried to cheer me up by saying,“Fifty is what forty used to be.”He had made an inspirational point.Am I over the hill?People keep telling me that the hill has been moved,and I keep telling them that the high-jump bar has dropped from the six feet I once easily cleared to the four feet that is impossible for me now.

“You’re not getting older,you’re getting better,”says Dr.Joyce Brothers.This,however,is the kind of doctor who inspires a second opinion.

And so,as I approach the day when I cannot even jump over the tennis net,I am moved to share some thoughts on aging with you.I am moved to show how aging feels to me physically and mentally.Getting older,of course,is obviously a better change than the one that brings you eulogies(悼词).In fact,a poet named Robert Browning considered it the best change of all:

Grow old along with me!

The best is yet to be.

Whether or not Browning was right,most of my first fifty years have been golden ones,so I will settle for what is ahead being as good as what has gone by.I find myself moving toward what is ahead with a curious blend(混合)of both fighting and accepting my aging,hoping that the philosopher(哲学家)was right when he said.“Old is always fifteen years from now.”

小题1:The author seems to tell us in Paragraph 1 that         .

A.time alone will tell

B.time goes by quickly

C.time will show what is right

D.time makes one forget the past小题2:When the author turned fifty,people around him         .

A.tried to comfort him

B.got inspirations from him

C.were friendlier with him

D.found him more talkative小题3:The author considers his fifty years of life         .

A.peaceful

B.ordinary

C.satisfactory

D.regretful小题4:We can infer from the passage that         .

A.the old should lead a simple life

B.the old should face the fact of aging

C.the old should take more exercise

D.the old should fill themselves with curiosity

判断题