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问题 选择题

分别将下列各组物质同时加到水中，得到无色、透明溶液的是

A．FeCl3、NaOH、KCl

B．Na2CO3、NaCl、K2SO4

C．BaCl2、NaOH、H2SO4

D．KCl、NaOH、CuSO4

答案

答案：B

题目分析：要得到无色透明溶液，A中FeCl3本身是黄色的，FeCl3和NaOH反应产生红褐色沉淀Fe(OH)3，不会得到无色透明溶液，故A错误；Ｂ中物质之间重新结合不会有水或气体或沉淀生成，且在水中都是无色的，故Ｂ正确；C．BaCl2与H2SO4会产生白色沉淀，不会得到无色透明溶液，故Ｃ错误；D．NaOH与CuSO4能产生蓝色沉淀，并且CuSO4溶液是蓝色的，故不合题意；故选Ｂ

单项选择题

Losing a job or not being able to find one almost always brings unwelcome changes. If you’ve lost a job, the first feeling is often one of shock. On top of the loss of income, many people find the whole routine of their life is shattered, their contact with other people reduced, their ambitions halted and their identity as a worker removed.
There may be good feelings too—it’s nice to be able to lie in bed in the morning, to spend more time with children, or to have more time to think—a better job may be just around the corner. But, unless a better job does turn up, chances are the days start getting longer and the time becomes harder to fill. Many people pass through periods of difficulty in sleeping and eating. They feel irritable and depressed, often isolated and lonely.
Despite all these problems, unemployment can be a chance for a fresh start. You can discover that it provides an opportunity to sort out or rethink what you want from life and how best you can get it. You can use the time to plan how to find a new job, learn a new skill, develop your hobbies, see if you can run your own business, do some voluntary work in your community or meet new people. It’s up to you.

The unemployed become finally disillusioned when they ______.

A．have nothing more to think about

B．are unable to improve their position

C．get tired of playing with their children

D．can no longer lie in bed in the morning
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单项选择题

关于A.RD.S的病理生理下列哪项不正确。（）

A.肺微血管壁通透性增加

B.肺间质水肿

C.通气/血流比例失调

D.肺内分流减少导致缺氧及二氧化碳潴留

E.肺泡群萎缩
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