碳二加氢反应器开车时,关于入口温度的控制正确的是()。A.温度越低越好 B.温度越高

题型:单项选择题

问题:

碳二加氢反应器开车时,关于入口温度的控制正确的是()。

A.温度越低越好

B.温度越高越好

C.控制在设计温度左右

D.没有特殊要求

考点:乙烯装置操作工乙烯反应器系统乙烯反应器系统题库
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(1)打点计时器所用电源为______,当电源频率为50Hz,每隔______s打一个点,实验时放开纸带与接通电源的先后顺序是先______.

(2)某同学在测定匀变速直线运动的加速度时,得到了几条较为理想的纸带,他已在每条纸带上按每5个点取好一个计数点,即两计数点之间的时间间隔为0.1s,依打点先后编为0,1,2,3,4,5.由于不小心,几条纸带都被撕断了,如图所示,请根据给出的A、B、C、D四段纸带回答:

在B、C、D三段纸带中选出从纸带A上撕下的那段应该是______,打A纸带时,物体的加速度大小是______m/s2

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明朝时,管辖东北女真的是()

A.乌思藏都司

B.奴儿于都司

C.朵甘都司

D.宣慰司

题型:单项选择题

健康信息的特点不包括()

A.容易理解

B.符号通用

C.针对性

D.预见性

E.指导性

题型:单项选择题

怎样寻找被埋压人员?

题型:单项选择题

根据短文内容,从短文后的选项中选出能填入空白处的最佳选项。选项中有两项为多余选项。

     When we think about happiness, we usually think of something extraordinary, a pinnacle (顶点) of sheer

(纯粹的) delight. And those pinnacles seem to get rarer the older we get. 

     1_____ I remember playing police and robbers in the woods, getting a speaking part in the school play.

Of course, kids also experience lows, but their delight at such peaks of pleasure as winning a race or getting

a new bike is unreserved.

     For teenagers, or people under 20 the concept of happiness changes. 2_____ I can still feel the pain of

not being invited to a party that almost everyone else was going to. I also remember the great happiness of

being invited at another event to dance with a very handsome young man.

     In adulthood the things that bring great joy-birth, love, marriage-also bring responsibility and the risk of

loss. 3_____ For Mulls, happiness is complex. 

     4_____ But I think a better definition (定义) of happiness is "the ability to enjoy something". The more

we can enjoy what we have, the happier we are. It's easy to overlook the pleasure we get from loving and

being loved, the company of friends, the freedom to live where we please, even good health.

     While happiness may be more complex for us, the solution is the same as ever. Happiness isn't about

what happens to us; it's the ability to find a positive for every negative (否定), and view a difficulty as a

challenge. 5_____

A. Love may not last; loved ones die.

B. For a child, happiness has a magic quality.

C. Happiness is the meaning and the purpose of life.

D. Being happy doesn't mean that everything is perfect.

E. The dictionary defines "happy" as "lucky" or "fortunate".

F. It's not wishing for what we don't have, but enjoying what we do possess.

G. Suddenly it's conditional on such things as excitement, love, and popularity.

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