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问题 单项选择题

下列实验设计和结论相符的是（）

A．将碘水倒入分液漏斗，加适量乙醇，振荡后静置，可将碘萃取到乙醇中

B．某气体能使湿润的红色石蕊试纸变蓝，该气体水溶液一定显碱性

C．某无色溶液中加Ba(NO3)2溶液，再加稀盐酸，沉淀不溶解，则原溶液中一定有

D．在含FeCl2杂质的FeCl3溶液中通入足量Cl2后，充分加热，除去过量的Cl2，即可得到较纯净的FeCl3溶液

答案

参考答案：B

解析：

本题涉及化学实验基础知识。乙醇和碘水互溶，不能用乙醇萃取碘水中的碘；C中溶液中如果含有，也可以出现相同的现象，因为在Ba(NO3)2溶液中加入盐酸后等于有了硝酸，硝酸具有强氧化性，能将氧化为；加热FeCl3溶液时，Fe3+会部分水解生成Fe(OH)3，得不到纯净的FeCl3溶液。

单项选择题

I first went to hear a live rock concert when I was eight years old. My brother and his friends were all fans of a heavy metal group called Black Wednesday. When they discovered that Black Wednesday were going to perform at our local theatre, they all bought (21) for the performance. However, at the last minute, once of the friends couldn’t go, so my brother offered me the ticket. I was really excited!

I remember the buzz (嘈杂声) of excitement inside the theatre as we all found our seats. After a few minutes, the lights went down and everybody became quiet. I could barely make out the stage in the (22) . We waited. Then there was a roar from the crowd, like an explosion, as the first members of the band stepped onto the stage. My brother leaned over and shouted something in my ear, but I couldn’t hear what he was saying. The first song was already starting and the music was as (23) as a jet engine. I could (24) the drum beats and bass notes in my stomach.

I can’t recall any of the songs that the band played. I just (25) that I really enjoyed the show and didn’t want it to (26) . But in the end, after three encores (加演), the show finished. We left the (27) and walked unsteadily out onto the pavement. I felt a little dizzy, as if I had just woken from a long sleep. My ears were still (28) with the beat of the last song.

After the (29) , I became a Black Wednesday fan too for a few years before getting into other kinds of music. Once in a while, though, I listen to one of their songs and (30) I’m back at that first show.

28().

A. aching

B. burning

C. ringing

D. rolling
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单项选择题

需弯曲加工的零件，下料时要求其弯曲线与材料的压延方向（）。

A.平行

B.垂直

C.成30º角

D.成60º角
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