关于核衰变和核反应的类型,下列表述正确的是( ) A.23892U→23490T

题型:问答题

问题:

关于核衰变和核反应的类型,下列表述正确的是(  )

A.

23892
U→
23490
Th+
42
He是β衰变

B.

147
N+
42
He→
178
O+
11
H是α衰变

C.

21
H+
31
H→
42
He+
10
n是轻核聚变

D.

8234Se→
8236
Kr+2
0-1
e是重核裂变

考点:核反应
题型:问答题

Many researchers have found greater dependence and obedience in very young girls, greater autonomy and activity in boys. When a barrier is set up to separate children from their mothers, boys try to knock it down; girls cry helplessly. There is little doubt that mother’s encouragement or discouragement—of such behavior plays a major role in determining adult personality. For example, a mother often stimulates male autonomy by throwing a toy far away from her young son, thus silently suggesting to him that he leaves her to get it.
Animal studies suggest that there may be a biological factor in material behavior; mothers of some monkeys punish their male babies earlier and more often than their female offspring; they also touch their female babies more often and act more protectively toward them.
As for the controversial question of female "passivity", psychologist Helen Deutsh believes that the concept has been misunderstood. "There is no contradiction between being feminine and working. The self can be active in both men and women," she says. It is only in love and sex that passivity is particularly appropriate for women. As she sees it, passivity is no more than a king of openness and warmth; it does not mean "inactivity of emptiness".
Another controversy ranges over the effect of hormones. Aggressive women; who discount hormonal influence, disagree violently with scientific researchers, who almost unanimously agree that hormones help determine how people feel and act. So far, there have been few studies of male hormones, but scientists think they may eventually discover hormonal cycles in men that produce cyclic changes in mood and behavior. As for females, studies have indicated that 49 percent of female medical and surgical admissions, most psychiatric hospital admission and 62 percent of violent crimes among women prisoners are related with hormonal cycles in women.

Many studies show that ______ .

A.boys are active and obedient to girls
B.girls are independent facing boys
C.boys are brave in getting what they want
D.girls don’t do anything in front of difficulties

题型:问答题

在《指南》中关于幼儿动作发展的目标有几条,分别是什么?

题型:问答题
图为远距离高压输电的示意图.关于远距离输电,下列表述不正确的是(  )

A.高压输电是通过减小输电电流来减小电路的发热损耗的

B.增加输电导线的横截面积有利于减少输电过程中的电能损失

C.在输送电压一定时,输送的电功率越大,输电过程中的电能损失越小

D.高压输电必须综合考虑各种因素,不一定是电压越高越好

题型:问答题

道路交通安全法规定,机动车第三者责任保险制度()。

A.自愿保险 

B.强制保险 

C.不须保险 

题型:问答题

四冲程汽油机与柴油机进气行程时进入汽缸的分别是()。

A.可燃混合气、纯空气

B.纯空气、可燃混合气

C.可燃混合气、可燃混合气

D.纯空气、纯空气

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