在物理实验中,要测定磁场的磁感应强度,可用一个探测线圈与一个冲击电流计(可测定通

题型:选择题

问题:

在物理实验中,要测定磁场的磁感应强度,可用一个探测线圈与一个冲击电流计(可测定通过电路的电荷量)串联后测量,原理图如图所示.若已测得匀强磁场的磁感应强度为B,又知探测线圈的匝数为n,面积为S,线圈与冲击电流计组成的回路电阻为R.实验开始时线圈平面与磁场垂直,若把探测线圈翻转180°,则此过程中冲击电流计测出的通过线圈的电荷量是(   )

A.

B.

C.

D.

考点:正弦式交变电流
题型:选择题

实验用兔首选的麻醉部位为()

A.双侧前肢静脉

B.双侧耳缘静脉

C.双侧足背静脉

D.颈浅静脉

E.双侧后肢静脉

题型:选择题

阅读理解。

     Liu Jiaoyang, 16, carefully winds a bobbin (绕线筒) with thread, places it on her sewing machine (缝纫机)

and then presses her foot down to begin sewing. While she's doing this, she pretends to guide fabric (布料)

through the machine. Liu looks forward to the class when she can work on a piece of real cloth, and make a

beautiful dress.

     Each Tuesday afternoon, after the bell rings for the fourth period, Liu becomes a fashion designer. At the

same time, the rest of the students at the High School Attached to Yunnan Normal University in Kunming are

also having classes a little bit different from the usual ones. Some students dance, others create robots, and still

others review films. These are just a few of the other 27 elective (选修的) courses besides Liu's sewing class

that the school began to offer last month.

     "The fashion design class has become the bright point of my week. I learn how to choose colors and fabrics

(织物) as well as sewing and sketching (素描) skills. It's all helping me to realize the dream of becoming a

fashion designer I've had since I was a little girl," Liu said.

     Design is Liu's favorite, but for other students the electives are interesting lessons which relieve (舒缓) the

pressures of schoolwork. Some students, for example, are learning how to play bridge. Chen Xi, 15, is one of

them. She said, "Many people think that playing a card game like this in class is a waste of time. But in fact,

bridge is a very challenging game that helps develop memory and math skills."

1. How often do the students have elective classes?

A. Once a week

B. Once a month

C. Once a term

D. Once a year

2. How often do the students have elective classes?

A. Once a week

B. Once a month

C. Once a term

D. Once a year

3. Why did the students like to have elective classes?

A. Because the elective classes are easier.

B. Because they needn't do any homework in the elective classes.

C. Because they can get an opportunity to relieve their pressures.

D. Because they want to be fashion designers in the future.

4. According to the passage many people think _____ in class is a waste of time.

A. dancing

B. creating robots

C. playing a card game

D. reviewing films

题型:选择题

临床上怀疑急性脑中风宜选择的检查方法有().

A.颅骨平片

B.血管造影

C.CT

D.MRI

E.脑室造影

题型:选择题

钱经理想采购食品加工设备,找到了3家比较满意的供应商,这时候他可以使用什么功能来对供应商进行筛选呢?()

A.询价单

B.竞价排名

C.批量询价

D.对比产品

题型:选择题

患者虚烦失眠,心悸不安,头目眩晕,咽干口燥,舌红,脉弦细,宜选用的方剂是()

A.酸枣仁汤

B.天王补心丹

C.朱砂安神丸

D.甘麦大枣汤

E.磁朱丸

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