问题 选择题

下列转化不能一步实现的是(  )

A.CO→CO2

B.H2O→H2

C.KNO3→KCl

D.Ca(OH)3→NaOH

答案

答案:C

题目分析:A、一氧化碳燃烧能生成二氧化碳,能一步实现.

B、电解水能生成氢气和氧气,能一步实现.

C、硝酸钾易溶于水,含有钾离子、硝酸根离子的化合物易溶于水,所以硝酸钾不能和其它物质反应生成氯化钾,不能一步实现.

D、氢氧化钙和碳酸钠能够发生复分解反应,生成氢氧化钠和碳酸钙,能一步实现.

故选:C.

点评:本题比较简单,只要熟记教材内容即可顺利解答.

问答题

The primitive root of the pleasure of parenthood is two-fold. (46) On the one hand, there is the feeling of part of one’s own body externalized, prolonging its life beyond the death of the rest of one’s body, and possibly in its turn externalizing part of itself in the same fashion, and so securing the immortality of the germ plasma. On the other hand there is an intimate blend of power and tenderness. The new creature is helpless, and there is an impulse to supply its needs, an impulse which gratifies not only the parent’s love towards the child, but also the parent’s desire for power. (47) So long as the infant is felt to be helpless, the affection which is bestowed upon it does not feel unselfish, since it is in the nature of protection to a vulnerable portion of oneself.

(48) But from a very early age there comes to be a conflict between love of parental power and desire for the child’s good, for, while power over the child is to a certain extent decreed by the nature of things, it is nevertheless desirable that the child should as soon as possible learn to be independent in as many ways as possible, which is unpleasant to the power impulse in a parent. Some parents never become conscious of this conflict, and remain tyrants until the children are in a position to rebel. Others, however, become conscious of it, and thus find themselves a prey to conflicting emotions. In this conflict their parental happiness is lost. (49) After all the care that they have bestowed on the child, they find to their mortification that he turns out quite different from what they had hoped. They wanted him to be a soldier, and they find him a pacifist, or, like Tolstoy, they wanted him to be a pacifist, and he joins the Black Hundreds.

But it is not only in these later developments that the difficulty is felt. (50) If you feed an infant who is already capable of feeding himself, you are putting love of power before the child’s welfare, although it seems to you that you are only been kind in saving him trouble. If you make him too vividly aware of dangers, you are probably actuated by a desire to keep him dependent upon you. If you give him demonstrative affection to which you expect a response, you are probably endeavoring to grapple him to you by means of his emotions. In a thousand ways, great and small, the possessive impulse of parents will lead them astray, unless they are very watchful or very pure in heart.

(46) On the one hand, there is the feeling of part of one’s own body externalized, prolonging its life beyond the death of the rest of one’s body, and possibly in its turn externalizing part of itself in the same fashion, and so securing the immortality of the germ plasma

单项选择题