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问题 选择题

根据所学化学知识，判断下列做法中完全正确的是

A．启用闲置的沼气池前先进行灯火实验

B．遇火灾时打开所有门窗

C．用燃着的木条可以鉴别空气、氧气、二氧化碳三瓶无色气体

D．家用电器着火，立即用大量水浇灭

答案

答案：C

A、沼气的主要成分是甲烷，甲烷具有可燃性，可燃性气体不纯时遇明火易产生爆炸，故不能进行灯火实验；

B、B、火灾发生时不能打开所有的门窗，否则空气会形成对流，增大室内氧气的浓度，火势更旺，故B不合理；

C、C、将燃着的木条分别伸进集气瓶中，燃烧现象物明显变化的是空气，木条燃烧更旺的是氧气，木条熄灭的是二氧化碳，现象不同，可以鉴别；

D、D、家用电器着火要先切断电源，不能立即用大量的水浇灭，故D不合理；

E、故选C．

选择题

“收乡长、镇将之权悉归于县，收县之权悉归于州，收州之权悉归于监司，收监司之权悉归于朝廷。”有关宋代上述做法的表述，错误的是（　　）。

A．目的是提高地方政府办事效率

B．有利于消除地方权重的弊端

C．造成地方政府权力过小

D．导致地方政府人浮于事
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完形填空

(共5小题。每小题2分．满分10分)

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。

May the first is an important date in the college admission process in the United States．This is the last day for high school seniors to accept or reject offers of admission in the fall．But according to a recent report，there is a great change．Acceptance rates at the top colleges this year were lower than ever．  61

These days，college applicants are applying to more colleges because online and common applications make the process easier．  62 On the other hand，it takes much time for top colleges to accept students．Students may not like being put on waiting lists．Also，common colleges make great efforts to get the students interested in them．Some colleges hold visiting days that offer a chance to attend classes and stay overnight．Some universities send gifts．  63 

For many families，the most important thing colleges can do is show them the money，especially this year；the weak economy makes parents nervous．  64 The recent problems that spread from the housing market to credit markets have even affected student's loans．So lately，top colleges have to spare lots of money to increase their financial aid for students．

  65  The Education Department expects the number of high school graduates to start to go down．This will happen as the last of the children of the baby boom generation finish high school．The number is not expected to start rising again until 2015．

A．Besides，top colleges are facing changes in the population．

B．What contributes to it?

C．But a mistake can be costly if it happens．

D．But top colleges ignore them．E．They have international students who know English．

F．It Can mean several acceptances to choose from．

G．They cannot afford college as planned．
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