某二叉树有5个度为2的结点，则该二叉树中的叶子结点数是( )。 A．10 B．8

意大利科学家使用普通氧分子（O₂）和带正电的氧离子制造出了一种新型的氧分子（O₄）．下列叙述中正确的是（　　）

A．是一种新型的化合物

B．一个分子中有两个分子

C．和O₂的化学性质完全相同

D．和O₂混合形成的是混合物

明朝时废除丞相制后，把朝廷的政务分割给[ ]

A．内阁

B．内书省

C．六部

D．锦衣卫

2001年6月13日凌晨2时许，张某因犯罪被公安机关监控，感到罪行即将暴露，便将此情况告诉了王某(系张某之妻)。随后，王某将藏于家中的作案工具五连发猎枪 1支及张某存放家中的五六式步枪子弹258发、赃款28．1万元等装入自己要出差用的行李箱里。凌晨5时许，王某带着两个大行李箱潜逃时，途中被公安人员在火车上抓获。王某的行为应该认定为：

A．窝藏转移赃物罪

B．非法持有枪支、弹药罪

C．非法携带枪支、弹药危及公共安全罪

D．数罪并罚

手机银行的哪些业务不收取手续费？（）

A、来账查询

B、同城系统内汇款

C、同城跨行汇款

D、公益捐款

Of all the areas of learning the most important is the development of attitudes. Emotional reactions as well as logical thought processes affect the behavior of most people.
"The burnt child fears the fire" is one instance ; another is the rise of despots like Hitler. Both examples also point up the fact that attitudes stem from experience. In one case the experience was direct and impressive; in the other it was indirect and cumulative. The Nazis were indoctrinated largely by the speeches they heard and the books they read.
The classroom teacher in the elementary school is in a strategic position to influence attitudes. This is true partly because children acquire attitudes from those adults whose word they respect.
Another reason it is true is that pupils often delve somewhat deeply into a subject in school that has only been touched upon at home or has possibly never occurred to them before. To a child who had previously acquired little knowledge of Mexico, his teacher’s method of handling such a unit would greatly affect his attitude toward Mexicans.
The media through which the teacher can develop wholesome attitudes are innumerable. Social studies (with special reference to races, creeds and nationalities) , science matters of health and safety, the very atmosphere of the classroom... these are a few of the fertile fields for the inculcation of proper emotional reactions.
However. when children come to school with undesirable attitudes, it is unwise for the teacher to attempt to change their feelings by cajoling or scolding them. She can achieve the proper effect by helping them obtain constructive experiences.
To illustrate, first grade pupils afraid of policemen will probably alter their attitudes after a classroom chat with the neighborhood officer in which he explains how he protects them. In the same way, a class of older children can develop attitudes through discussion, research, outside reading and all-day trips.
Finally, a teacher must constantly evaluate her own attitudes, because her influence can be deleterious if she has personal prejudices. This is especially true in respect to controversial issues and questions on which children should be encouraged to reach their own decisions as a result of objective analysis of all the facts.

The central idea of the above passage is that ______.

A．attitudes affect our actions

B．teachers are important in developing or changing pupils’ attitudes

C．attitudes can be changed by some classroom experiences

D．by their attitudes, teachers inadvertently affect pupils’ attitudes