据报道:爆炸性的高能N5+阳离子(氮元素的原子序数为7)被美国加州空军基地研究高

题型:选择题

问题:

据报道:爆炸性的高能N5+阳离子(氮元素的原子序数为7)被美国加州空军基地研究高能材料的化学家合成,关于N5+的说法正确的是:(  )

A.该粒子的质子数为34

B.该粒子由5个氮分子构成

C.该粒子的电子数为34

D.它是一种由5个氮原子构成的单质分子

考点:分子的定义验证分子特点的实验离子结构示意图构成物质的微粒(分子、原子、离子)
题型:选择题

二元一次方程2x+y=7的正整数解有______个.

题型:选择题

掷一均匀的正方形骰子,骰子每个面分别标了数字1,2,3,4,5,6,则

(1)P(掷得点数3)=(    )。

(2)P(掷得点数是奇数)=(    )。

(3)P(掷得点数是偶数)=(    )。

(4)P(掷得点数不大于5)=(    )。

(5)P(掷得点数不小于7)=(    )。

(6)P(掷得数是两位数)=(    )。

(7)P(掷得数是2的倍数)=(    )。

题型: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.

5()

A.with

B.from

C.into

D.beyond

题型:选择题

《海底两万里》中诺第留斯号潜艇是船长尼莫在大洋中的一座荒岛上秘密建造的,船身坚固,利用()发电。

题型:选择题

网内往来机构在工作时间内应及时处理往来账业务。需人工核销的贷记来账应在收到来账当日至迟不超过()个工作日核销完毕。

A、一

B、二

C、三

D、四

更多题库