问题 问答题 简答题

水泵启动前的引水方法有几种,各用在什么地方?

答案

参考答案:

水泵启动前引水的方法可分为两大类,吸水管带有底阀和吸水管不带底阀。

(1)吸水管带有水下底阀:①高架水箱灌水:一般用于小型水泵(水泵吸水管径在300mm以下),压水管路内常因停泵而泄空无水,吸水管路较短所需注入水量不多。②压水管引水:一般用于小型水泵(水泵吸水管径在300mm以下),压水管路内常有水。

(2)吸水管带有水上底阀:③水上底阀引水:用于小型水泵(水泵吸水管径在400mm以下)。

(3)吸水管不带底阀:④真空泵直接引水:适用于启动各种规模型号水泵。尤其适合大、中型水泵及吸水管道较长时。⑤真空泵常吊真空引水:用于启动中、小规模型号水泵较多,大型水泵使用较少;适用于虹吸进水系统。⑥液(气)射流泵、水射器引水:适用于小型水泵。⑦自吸泵(自吸式离心泵):适用于水泵频繁启动的场合

阅读理解

请阅读下列应用文及相关信息,按照要求匹配信息,并把答案填涂在答题卡的相应位置上。填涂选项中有一项为多余项。

下面文章中有5处(第71~75题)需要添加小标题,请从以下选项中选出符合各段意思的小标题,并在答题卡上将该项涂黑,选项中一项为多余选项.

A.Slow Down Your Life

B.Escape Now and Then

C.Separate Your Actions

D.Allow Yourself to Be WeakE. Relieve Pressure by Firmly Saying “ No”

F. Stop Expecting Everything to Be Perfect

How to Simplify Your Life

Less is more.This is why we say: reduce things by half instead of doubling them, get rid of junk instead of piling it up, relax instead of stressing, slow down instead of speeding up.Apply these principles in your everyday life in a conscious way.You will then find yourself well along on your journey to simplification.

1.___ _______.

When you concentrate on one task, you find you have energy that you didn't even know you had.Just imagine: you are at a fair and you have to carry two heavy pigs over 100 yards.If you keep grabbing one and then the other, it will take forever, because one of them will keep slipping out from under your arm and running off.But if you tie one pig in a place, pick up the other, gather all your strength and make a dash for the finish line, pause for a moment, run back and get the other one, and with great determination, carry the second pig to the finish line, then you can be sure of success.

2.__________.

The pressure at work is on the increase in all occupations.In the modern nuclear family, the expectations that formerly would have been shared among all the relatives are now concentrated on the individual partner.

If you have the feeling that 24 hours per day are not enough for all the things you need to do, then it’s not because the day has too few hours, but because you have too many activities.A simple fact that overloaded people often tend to forget.The solution is equally simple: refuse to accept so many work assignments in your private life or your working life.

3. ______.

“I can handle stress” is regarded as a positive statement in the world of work.People who can handle stress are given more and more to cope with — until one day they break.

Pay careful attention to the signs that tell you that you are under more stress than you can cope with.These signals came from various areas of life.You become ill, or your work efficiency decreases.

If you have any of these symptoms, change your life goals and decrease your tolerance of stress.Say quite openly, "I can't manage that."

4. _____.

"If only I were slimmer, more beautiful, richer, cleverer, then I would be happier." This is a dream that makes a lot of people ill, depressed, and unhappy.Life has its flaws, defects, comets, and edges.Only those who accept this reality can lead a really full life.

Of course there are activities in which errors are dangerous; driving a car, crossing the road.But life doesn't consist entirely of these things.In among them there is a lot of room for small and large mistakes.

5.___________.

Successful people all have their own places where they can withdraw in order to work.Find out which places improve your creativity.For me it's the train.When I know that I'm going to be traveling for four hours without phone calls and people knocking on my door, I find my mind is free and I can read or write complex articles.There can be problems working on the train, of course: if the person sitting opposite you keeps talking away, or if train trips make you tired (some people fall asleep after a few miles).

单项选择题