问题 填空题

我们学到的很多化学用语中都含有一些数字,你了解它们各自的含义吗?试着将下面化学用语中加点数字2的含义表示出来.

(1)2O______;

(2)O2______;

(3)2H2O______:

(4)SO42-______;

(5)2NH4+______;

(6)

+2
Ca
O______.

答案

(1)2的后面是元素符号表示两个氧原子;

(2)2在右下角表示一个氧分子中含有两个氧原子;

(3)2的后面是水的化学式,所以表示分子个数,表示两个水分子;

(4)2在硫酸根的右上角表示一个硫酸根离子带2个单位负电荷;

(5)2后面是铵根离子表示两个铵根离子;

(6)2在氧的正上方表示氧化钙中氧的化合价-2价.

故答案为:(1)2个氧原子;(2)一个氧分子中含有2个氧原子;(3)2个水分子;(4)一个硫酸根离子带2个单位负电荷;(5)2个铵根离子;(6)氧化钙中氧的化合价-2价.

填空题


In the following passage, there are 25 blanks representing words that are missing from the context. You are to put back in each of the blanks with the missing word. Write your answers on the ANSWER SHEET. The time for this section is 25 minutes.
Compared with the immediate practical responsibility of the scientist, the (1) of the artist must seem puny. The decision which faces (2) is not one of practical action: of course he will try to throw this (3) into the scale, and that weight, if he is a writer or (4) a painter of genius, may have its effect. For the novelist—in our society the only artist who has a mass audience and at the same time effective economic control of the means of addressing (5) —the hope of some decisive influence is a reasonable (6) . For him, since he takes of all artists (7) is probably the largest portion of his culture as material, there is no (8) escape from the necessity for treating the content of his work seriously than (9) is for the social psychologist he is coming so closely to resemble. The dichotomy which people have tried to establish between artistic proficiency and (10) content is becoming unbearable to almost all sensitive minds. I doubt if it has ever been real— we might have admired Shelley as (11) if he had been indifferent to such things as war and tyranny, though I doubt it; certainly (12) he been indifferent we should never have been led by (13) .
There is no Hippocratic oath in literature, and I am not attempting to draw (14) up. As far as I am concerned, the artist is a human being writ large and his (15) are the ethics of any human being. Perhaps I can best illustrate (16) seems to me the new (17) of those duties of assertion and refusal from one writer, and I do not (18) it is without significance that this (19) projects the whole situation of choice into a scientific parable, the (20) of a pestilence: a (21) many human (22) are called to fight against, called not by any supernatural (23) but by the simple fact that the fight against a plague is (24) like a biological human (25) .

单项选择题