可能发生肩难产的因素有哪些A.巨大胎儿 B.B超测定胎儿胸径大于双顶径 C.巨大胎儿

题型:多项选择题

问题:

可能发生肩难产的因素有哪些

A.巨大胎儿

B.B超测定胎儿胸径大于双顶径

C.巨大胎儿合并产程图减速期延长或第二产程大于1小时

D.困难的 * * 助产或宫口开全后胎头双顶径仍滞留在中骨盆平面

E.糖尿病患者的巨大胎儿

考点:卫生资格考试(中初级)妇产科专业知识妇产科主治医师专业知识
题型:多项选择题

某一直流电动机提升重物的装置如图所示,重物的质量m=5kg,g=9.8m/s2,电源提供的电压U=110V,不计一切摩擦,当电动机以v=0.9m/s的恒定速度向上提升重物时,电路中的电流I=0.5A,求:

(1)由此可知电动机线圈的电阻R是多少?

(2)电动机的反电动势为多少?

题型:多项选择题

阅读理解。

     American society is not nap (午睡)-friendly. In fact, says David Dinges, a sleep specialist

at the University of Pennsylvania School of Medicine,"There's even a prohibition against admitting

we need sleep". Nobody wants to be caught napping or found asleep at work. To quote a

proverb:"Some sleep five hours, nature requires seven, laziness nine and wickedness eleven."

     Wrong. The way not to fall asleep at work is to take naps when you need them."We have to

totally changeour attitude toward napping,"says Dr. William Dement of Stanford University, the

godfather of sleep research.

     Last year a national commission led by Dement identified an"American sleep debt" which one

member said was as important as the national debt. The commission was concerned about the

dangers of sleepiness: people causing industrial accidents or falling asleep while driving. This may

be why we have a new sleep policy in the White House. According to recent reports, President

Clinton is trying to take a ha1f-hour snooze (瞌睡) every afternoon.

     About 60 percent of American adults nap when given the opportunity. We seem to have"a

mid afternoon quiet phase," also called "a secondary sleep gate." Sleeping 15 minutes to two

hours in the early afternoon can reduce stress and make us refreshed. Clearly, we were born

to nap.

     We Superstars of Snooze don't nap to replace lost shut-eye or to prepare for a night shift.

Rather, we "snack" on sleep, whenever, wherever and at whatever time we feel like it. I myself

have napped in buses, cars, planes and on boats; on floors and beds; and in libraries, offices

and museums.

l. It is commonly accepted in American society that too much sleep is ._____

A. unreasonable

B. criminal

C. harmful

D. costly

2. The research done by the Dement Commission shows that Americans ________.

A. don't like to take naps

B. are terribly worried about their national debt

C. sleep less than is good for them

D. have caused many industrial and traffic accidents

3. The purpose of this article is to.______

A. warn us of the wickedness of napping

B. explain the danger of sleepiness

C. discuss the side effects of napping

D. convince the reader of the necessity of napping

4. The underlined phrase "American sleep debt" in Para. 3 is the result of ._____

A. the traditional misconception the Americans have about sleep

B. the new sleep policy of the Clinton Administration

C. the rapid development of American industry

D. the Americans' worry about the danger of sleepiness

5. The second sentence of the last paragraph tells us that it is .______

A. preferable to have a sound sleep before a night shift

B. good practice to eat something light before we go to bed

C. essential to make up for cost sleep

D. natural to take a nap whenever we feel the need for it

题型:多项选择题

蛋白质聚丙烯酰胺凝胶电泳的电泳缓冲液是

A.Tris—乙酸缓冲液
B.Tris—硼酸缓冲液
C.Tris—磷酸缓冲液
D.Tris—甘氨酸缓冲液
E.碱性缓冲液

题型:多项选择题

根据火焰明暗不同,烤的方法主要有______。

A.明火烤

B.暗火烤

C.炭火烤

D.果木烤

E.地坑烤

F.火槽烤

题型:多项选择题

诊断应首先考虑

A.狼疮性肺炎

B.浸润型肺结核

C.纤维空洞型肺结核

D.支气管肺癌

E.结节病

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