关于抗体的功能，错误的有A．中和毒素 B．通过胎盘 C．结合抗原 D．杀伤靶细胞 E

已知小球沿倾角为θ的光滑斜面下滑时加速度大小为gsinθ。现用长度为L的铁丝绕成一个高度为H的等螺距螺旋线圈，将它竖直地固定于水平桌面。穿在铁丝上的一珠子可沿此螺旋线无摩擦地下滑。则这个小珠子从螺旋线圈最高点无初速滑到桌面经历的时间t=（ ）

A．

B．L

C．

D．L

颈部旋转、伸展时，提示关节受刺激的是（）

A.颈部旋转时疼痛弥散

B.颈部旋转时局限性剧痛

C.颈部旋转时肌紧张定位明确

D.颈部伸展时肩头区或肩胛区的牵涉痛

E.颈部伸展时臂或手相应皮节的牵涉剧痛

下列关于公共卫生社会工作的陈述中，不恰当的是（）。

A.强调促进健康、保护环境

B.公共卫生社会工作从群体入手

C.实务方法是社区评估和社会流行病调查

D.强调疾病预防

阅读理解。

     Margaret, married with two small children, has been working for the last seven years as a night cleaner,

cleaning offices in a big building.

     She trained as a nurse, but had to give it up when her elder child became seriously ill. "I would have liked

to go back to it, but the shifts (工作班次) are all wrong for me, as I have to be home to get the children up

and off to school."

     So she works as a cleaner instead, from 9 a.m. till 6 a.m. five nights a week for just ￡90, before tax and

insurance. "It's better than it was last year, but I still think that people who work 'unsocial hours' should get

a bit extra."

     The hours she' s chosen to work meant that she sees plenty of the children, but very little of her husband.

However, she doesn't think that puts any pressure on their relationship.

     Her work isn't physically very hard, but it's not exactly pleasant, either. "I do get angry with people who

leave their offices like a place for raising pigs. If they realized people like me have to do it, perhaps they'd be

a bit more careful."

     The fact that she's working all night doesn't worry Margaret at all. Unlike some dark buildings at night, the

building where she works is fully lit, and the women work in groups of three. "Since I've got to be here, I try

to enjoy myself-and I usually do, because of the other girls. We all have a good laugh, so the time never

drags."

     Another challenge Margaret has to face is the reaction of other people when she tells them what she does

for a living. "They think you're a cleaner because you don't know how to read and write," said Margaret. "I

used to think what my parents would say if they knew what I'd been doing, but I don't think that way any

more. I don't dislike the work though I can't say I'm mad about it."

1. Margaret quit her job as a nurse because _______

A. she wanted to earn more money to support her family

B. she had suffered a lot of mental pressure

C. she needed the right time to look after her children

D. she felt tired of taking care of patients

2. Margaret gets angry with people who work in the office because Margaret _______.

A. they never clean their offices

B. they look down upon cleaners

C. they never do their work carefully

D. they always make a mess in their offices

3. When at work, Margaret feels _______.

A. light-hearted because of her fellow workers

B. happy because the building is fully lit

C. tired because of the heavy workload

D. bored because time passed slowly

4. The underlined part in the last paragraph implies that Margaret's parents would _______．

A. help care for her children

B. regret what they had said

C. show sympathy for her

D. feel disappointed in her

如图所示，竖直面内的虚线上方是一匀强磁场B，从虚线下方竖直上抛一正方形线圈，线圈越过虚线进入磁场，最后又落回原处，运动过程中线圈平面保持在竖直平面内，不计空气阻力，则：

A．上升过程克服磁场力做的功大于下降过程克服磁场力做的功

B．上升过程克服磁场力做的功等于下降过程克服磁场力做的功

C．上升过程克服重力做功的平均功率大于下降过程中重力的平均功率

D．上升过程克服重力做功的平均功率等于下降过程中重力的平均功率