搜题请搜索小程序“爱下问搜题”
问题 填空题

物理学规定：__________电荷定向移动方向为电流方向。（“正”或“负”）

答案

正

题目分析：电荷的定向移动形成电流，有三种情况：正电荷定向移动形成电流；负电荷定向移动形成电流；正负电荷向相反方向移动形成电流．物理学规定：把正电荷定向移动的方向规定为电流的方向．故答案为：正．

单项选择题 A1/A2型题

关于代谢性碱中毒的特点，以下正确的是（）.

A.HCO3-／H2CO3＜20／1，原发性H2CO3↑

B.HCO3-／H2CO3＜20／1，原发性HCO3-↓

C.HCO3-／H2CO3＞20／1，原发性H2CO3↑

D.HCO3-／H2CO3＞20／1，原发性HCO3-↑
查看答案
单项选择题

Culture is activity of thought, and receptiveness to beauty and human feeling. (1) of information have nothing to do with it. A merely well-informed man is the most useless (2) on God’s earth. What we should (3) at producing is men who (4) both culture and expert knowledge in some special direction. Their expert knowledge will give them the ground to start (5) , and their culture will lead them as (6) as philosophy and as high as (7) We have to remember that the valuable (8) development is self-development, and that it (9) takes place between the ages of sixteen and thirty. As to training, the most important part is given by mothers before the age of twelve.

In training a child to activity of thought, above all things we must (10) of what I will call "inert ideas"—— that is to say, ideas that are merely (11) into the mind without being (12) , or tested, or thrown into fresh combinations.

In the history of education, the most (13) phenomenon is that schools of learning, which at one epoch are alive with a craze for genius, in a (14) generation exhibit merely pedantry and routine. The reason is that they are overlade with inert ideas. Except at (15) intervals of intellectual motivation, education in the past has been radically (16) with inert ideas. That is the reason why (17) clever women, who have seen much of the world, are in middle life so much the most cultured part of the community. They have been saved from this horrible (18) of inert ideas. Every intellectual revolution which has ever stirred humanity (19) greatness has been a (20) protest against inert ideas.

19（）

A.off

B.on

C.into

D.with
查看答案