制氢站着火时,如何进行扑救?

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问题:

制氢站着火时,如何进行扑救?

考点:电厂化学设备检修工考试电厂化学设备检修工考试题库
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已知椭圆C1
x2
a2
+
y2
b2
=1(a>b>0)
的离心率为
2
2
,直线l:y=x+2
2
与以原点为圆心、以椭圆C1的短半轴长为半径的圆相切.
(Ⅰ)求椭圆C1的方程.
(Ⅱ)设椭圆C1的左焦点为F1,右焦点为F2,直线l1过点F1,且垂直于椭圆的长轴,动直线l2垂直l1于点P,线段PF2的垂直平分线交l2于点M,求点M的轨迹C2的方程;
(Ⅲ)若AC、BD为椭圆C1的两条相互垂直的弦,垂足为右焦点F2,求四边形ABCD的面积的最小值.
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宇宙是由______组成的,物质是由______组成的.世界上的物质有多种形态,我们身边的物质一般以______的形式存在.

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关于非少尿型急性肾衰竭,下列错误的是()。

A.少尿不明显

B.症状轻

C.多发生于大手术后

D.BUN及Cr进行性升高

E.预后较少尿型肾衰竭差

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舟山渔场、长芦盐场和莺歌海盐场分别所属的海区是

①渤海②黄海③东海④南海[ ]

A.④②①

B.③②④

C.②①③

D.③①④

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Come on—Everybody’s doing it. That whispered message, half invitation and half forcing, is what most of us think of when we hear the words peer pressure. It usually leads to no good—drinking, drugs and casual sex. But in her new book Join the Club, Tina Rosenberg contends that peer pressure can also be a positive force through what she calls the social cure, in which organizations and officials use the power of group dynamics to help individuals improve their lives and possibly the word.

Rosenberg, the recipient of a Pulitzer Prize, offers a host of examples of the social cure in action: In South Carolina, a state-sponsored antismoking program called Rage Against the Haze sets out to make cigarettes uncool. In South Africa, an HIV-prevention initiative known as LoveLife recruits young people to promote safe sex among their peers.

The idea seems promising, and Rosenberg is a perceptive observer. Her critique of the lameness of many pubic-health campaigns is spot-on: they fail to mobilize peer pressure for healthy habits, and they demonstrate a seriously flawed understanding of psychology. "Dare to be different, please don’t smoke!" pleads one billboard campaign aimed at reducing smoking among teenagers teenagers, who desire nothing more than fitting in. Rosenberg argues convincingly that public-health advocates ought to take a page from advertisers, so skilled at applying peer pressure.

But on the general effectiveness of the social cure, Rosenberg is less persuasive. Join the Club is filled with too much irrelevant detail and not enough exploration of the social and biological factors that make peer pressure so powerful. The most glaring flaw of the social cure as it’s presented here is that it doesn’t work very well for very long. Rage Against the Haze failed once state funding was cut. Evidence that the LoveLife program produces lasting changes is limited and mixed.

There’s no doubt that our peer groups exert enormous influence on our behavior. An emerging body of research shows that positive health habits—as well as negative ones—spread through networks of friends via social communication. This is a subtle form of peer pressure: we unconsciously imitate the behavior we see every day.

Far less certain, however, is how successfully experts and bureaucrats can select our peer groups and steer their activities in virtuous directions. It’s like the teacher who breaks up the troublemakers in the back row by pairing them with better-behaved classmates. The tactic never really works. And that’s the problem with a social cure engineered from the outside: in the real world, as in school, we insist on choosing our own friends.

According to the first paragraph, peer pressure often emerges as()

A. a supplement to the social cure

B. a stimulus to group dynamics

C. an obstacle to school progress

D. a cause of undesirable behaviors

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