题干

萃取碘水中的碘,可用的萃取剂是①四氯化碳 ②汽油 ③酒精

A:只有①

B:①和②

C:①和③

D:①②③

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答案(点此获取答案解析)

B

同类题1

阅读文章,回答问题。

享受春雨      

                            (厉彦林)

    ①也许是刚经历了冬天太多的郁闷和压抑,也许是寒风、残雪在记忆的底片上留下太多的沧桑与悲凉,万物掐灭生命的色彩与声音,孤独地萧条着沉默着。一夜微风,唤醒早春三月的晨曦,也吹来了北方第一场春雨。山川、河流、乡村、房屋、树林、花草、庄稼、庄稼人,都在翘首春的惠风拂面,享受春雨的滋润,感觉春天那年轻的心跳……
    ②春雨如烟,如雾,如丝,如梦,悄悄落下来,一滴一滴,淅淅沥沥,飘飘洒洒,缠缠绵绵。恰似烟雾迷蒙、若有若无、若即若离的水墨画,朦胧且迷人。春雨婀娜多姿,巧笑倩兮,步履轻盈,委婉含蓄,率性天然,没有夏雨的暴烈,没有秋雨的忧愁,没有冬雨的冷酷,像位清纯、含蓄待嫁的新娘,充满对生命、对世间万物的爱恋……为了履行前世约定,悄无声息地把睡梦中的大地山川抚摩一遍,湿润着每一个角落、每一棵小草。令人悄然想起“小楼一夜听春雨,深巷明朝卖杏花”的美妙佳句。一会儿工夫,雨点越来越大,越来越急,嘻嘻哈哈,打打闹闹,在干燥的土地上留下密密匝匝的雨窝。春雨从不埋怨和选择土地肥沃或贫瘠,总是执着地投入,迅速渗进地下,形不成水流,只让土地守候和感动,让世人留恋和感叹。
    ③走在乡间小路上,任细细的雨丝自由地落在脸上,痒酥酥的,滑到嘴里,甜丝丝的。此时可以真正感受与大自然亲密接触的惬意与舒畅。我记得在老家院中赏雨的情景。雨点劈里啪啦掉下来了,洒在头上,落在脸上,说不清道不明的舒爽。我忘情地站在雨里,虽然衣服被打湿,可心里高兴,脸上绽放着笑容,享受着那份难得的清凉和惬意。院里的梧桐树耸立雨中,紫红的小芽芽摇曳着甜美的心事。枝杈上被雨淋过的喜鹊窝颜色更加凝重,淘气的小喜鹊躲在老喜鹊的翅膀下,时而从窝里探出小脑袋,新奇地瞥一眼外面的风景,又唧唧喳喳地把头缩回去。树下有一群相互依偎的鸭子,时而用嘴巴梳理着羽毛,呱呱地交流着什么。那鸟鸣声、鸭叫声,伴随风声雨声,滋润,清雅,恬淡,宁静……
    ④春雨贵如油,老天爷也十分小气。雨刚下了一会儿,就停了。雨虽然不大,却滋润着乡间万物,悄然改变了山乡的颜色,编织出一幅绚丽多姿的图画,点燃了生命的期待与呼唤!……草儿绿了,花儿开了,土地松软了,生命以最简单、最自然的方式在繁衍、传承、轮回。前两天还光秃秃的山冈,奇迹般地罩上了新绿。真可谓浓妆淡抹总相宜。大地是藏梦、长梦的地方!萌生绿色的地方就舒展生命,就有开花的渴望,就有歌声在酝酿!每人都种植一份鲜嫩的心境,收获一缕成长的愿望。
    ⑤春雨是会说会笑的精灵,是律动生命的音乐。春雨会跟随着气候幻化不同姿态、不同神情,也会随听雨者心情演绎不同的内涵。或嫣然,或惆怅,或温柔,或冷寂,或清丽,或婉约……可谓千种心情,万种雨境。(原载《 人民日报 》,有删改)

同类题5

    The mystery stories of Sir Arthur Conan Doyle are famous all over the world.
    The detective in his stories is called Sherlock Holmes. He solves mysteries in a most surprising way. His assistant, Dr Watson, watches with admiration and then writes up the story of the mystery afterwards.
    This is a useful story writing skill. Because Watson is not very clever, the story remains a mystery until the end. The readers can sometimes pick up some clues before he does! Then, to make Watson understand the mystery, Holmes has to explain it all, step by step. So we, the readers, get to see it step by step too. Watson is almost as good a character in the story as Sherlock Holmes!
    The very first time they meet, Holmes greatly surprises Watson. When they are first introduced, Holmes says to Watson, ‘How do you do? I see you have been to Afghanistan(阿富汗).’
    Watson is too amazed by this to ask Holmes how he knows this. Watson has, indeed, been to Afghanistan. Later, he asks Holmes about it. Holmes explains that there is nothing magical about what he does. He gets to know it all by very, very careful observation(观察).
Observation One
    Watson was introduced to Holmes as a doctor. Yet Holmes thought that the way he stood and walked made him seem like a soldier. So, this meant he was probably an army doctor.
Observation Two
    Watson's face was quite dark skinned. But his wrists were pale. So his dark face was probably sun burnt. This meant that he had been to a hot, sunny country.
Observation Three
    At the time, the British army had soldiers at bases in many parts of the world. So there were still a lot of places to choose from. However, Holmes saw that Watson looked very tired and he was always holding his left arm, as if it was painful. So, he had probably been with the army to a place where they were fighting. There was only one place where the British army was fighting at that time: Afghanistan.