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问题 填空题

有限的元素可组成种类繁多的物质．依据表中的元素回答下列问题．

元素名称氢碳氧氯锰铁
元素符号HCOClMnFe
 

（1）A溶液在黑色固体B的作用下生成无色气体D，D与生命活动息息相关．A溶液中的溶质用化学式表示为　           　．

（2）无色气体E与红色固体F在一定条件下反应，得到固体G，反应的化学方程式为　          　．

（3）将一定量的固体G放入一定量且过量M溶液中，能发生反应，观察到的现象是　           　．

（4）向（3）所得溶液中加入适量A溶液，溶液变为黄色，且溶质仅有一种，该反应的化学方程式

为　　                                    ．

答案

（1）H2O2．（2）3CO+Fe2O33CO2+2Fe．（3）固体消失，有气泡产生溶液变为浅绿色．（4）2FeCl2+H2O2+2HCl=2FeCl3+2H2O

题目分析：（1）二氧化锰是黑色固体，双氧水是液体，双氧水在二氧化锰的催化作用下生成氧气，氧气与生命活动息息相关，故A溶液为双氧水溶液，化学式为H2O2（2）由上述元素组成的红色固体为氧化铁，无色气体一氧化碳能与氧化铁反应生成铁，故E为一氧化碳，F为氧化铁，G为铁，反应的化学方程式为 3CO+Fe2O33CO2+2Fe．（3）由（2）可知G为铁，铁能与盐酸反应生成氯化亚铁和氢气，观察到的现象是 固体消失，有气泡产生溶液变为浅绿色．（4）由（3）可知所得溶液中的溶质为生成的氯化亚铁和过量的盐酸，A溶液为双氧水溶液，溶液变为黄色，且溶质仅有一种，因此反应后溶液中的溶质为氯化铁，该反应的化学方程式为 2FeCl2+H2O2+2HCl=2FeCl3+2H2O．

选择题

19世纪中后期，当世界加速迈向近代化时，下列人物也正以一场运动引领着中国“与时俱进”。他们的这场运动在客观上对封建制度起到（  ）

A．补充作用

B．瓦解作用

C．改革作用

D．巩固作用
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单项选择题

Personality is to a large extent inherent. A-type parents usually (1) A-type offspring. But the environment must also have a profound effect (2) if competition is important to the parents, it is (3) to become a major factor in the lives of their children.

One place where children (4) A characteristics is school, which is, (5) its very nature, a highly competitive institution. Too many schools (6) the "win at all costs" moral standard and measure their success by sporting achievements. The current (7) for making children compete against their classmates or against the (8) produces a two-layer system, in which competitive A types seem in some way better than their B type fellows. Being too (9) to win can have dangerous consequences: remember that Pheidippides, the first marathon runner, (10) dead seconds after saying. "Rejoice, we conquer!"

(11) the worst form of competition in schools is the disproportionate emphasis on examinations. There is, for example, a (12) school that allows pupils to concentrate on those things they do well. The (13) of competition by examination are somewhat questionable, but competition in the certain (14) of failure is positively harmful.

(15) , it is neither practical nor desirable that all A youngsters change into B’s. The world needs types, and schools have an important duty to try to (16) a child’s personality to his possible future employment. It is top management.

If the preoccupation of schools with academic work was (17) , more time might be spent teaching children surer values. Perhaps selection (18) the caring professions, especially medicine, could be made less by good grades in chemistry and more by such (19) as sensitivity and sympathy. It is surely a mistake to choose our doctors exclusively from A type stock. B’s are important and should be (20) .

4（）

A. draw on

B. get over

C. drag on

D.soak up
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