如图所示,在y轴竖直向上的直角坐标系中,电场、磁场的分布情况如下: ①在o<y<

题型:问答题

问题:

如图所示,在y轴竖直向上的直角坐标系中,电场、磁场的分布情况如下:

①在o<y<α口的区域内,存在沿x轴负向的匀强电场和垂直xoy平面向里的匀强磁场;

②在y<o区域内,存在沿y轴正向的匀强电场;

③在y<y1区域内,同时存在垂直xoy平面向外的匀强磁场;

各区域的电场、磁场强弱相同.一质量为m、电量为q带正电的小球,从xoy平面内的P点以初速v0向右抛出.小球进入0<y<α的复合场区沿直线运动,恰好过坐标原点,方向如图.如果小球能够第二次到达O点,m、α、v0、q、g为已知量,求:

(1)p点坐标;

(2)磁感应强度B;

(3)小球两次通过O点经历的时间.

考点:带电粒子在电场中运动的综合应用带电粒子在匀强磁场中的运动
题型:问答题

由B淋巴细胞介导的免疫应答称为________,发挥免疫效应的物质主要是________。

题型:问答题

阅读理解。

     Every country tends to accept its own way of life as being the normal one and to praise or

criticize others,as they are similar to or different from it.And unfortunately,our picture of the

people and the way of life of other countries is often a distorted (扭曲的) one.

     Here is a great argument in favor of foreign travel and learning foreign languages.It is only

by traveling in a country and getting to know its inhabitants and their language that one can

find out what a country and its people are really like.And how different the knowledge one

gains this way frequently turns out to be from the secondhand information gathered from

other sources! How often we find that the foreigners whom we thought to be such different

people from ourselves are not very different at all!

     Differences between peoples do,of course,exist and,one hopes,will always continue to

do so.The world will be a dull place indeed when all the different nationalities behave exactly

alike,and some people might say that we are rapidly approaching this state of affairs.With the

much greater rapidity (快速) and ease of travel,there might seem to be some truth in this at

least as far as Europe is concerned.However this may be,at least the greater ease of travel

today has revealed (展示) to more people than ever before that the Englishman or Frenchman

or German is not:some different kind of animal from themselves.

1.Every country criticizes ways of life in other countries because they are________.

A.distorted

B.normal

C.similar to each other

D.different from its own

2.One who travels in a foreign country and learns its language will________.

A.find out why its people are different

B.argue in favor of this country and the language

C.know the country and its people better

D.like its inhabitants and their language

3.The knowledge one gains by traveling in a foreign country is often________.

A.from secondhand information

B.gathered from other sources rather than its inhabitants

C.gained from the arguments about the country

D.different from what one had before the travel

4.In this passage,the author wants to say________.

A.differences between peoples will gradually disappear because of the ease of travel

B.differences between peoples do exist even though different nationalities behave exactly alike

C.differences between peoples will continue to exist and the world will be a dull place

D.differences between peoples will not exist as one hopes

题型:问答题

五磨饮子加减治疗:

A.腹大胀满,按之如囊裹水
B.腹大胀满,脉络怒张
C.腹大胀满不舒,早宽暮急
D.腹大胀满,舌红绛少津
E.腹大胀满,脘腹撑急

题型:问答题

有关急性播散性脑脊髓炎的辅助检查不正确的是()。

A.外周血白细胞增多,血沉加快

B.脑脊液压力增高或正常,CSF-MNC增多

C.CSF蛋白明显增高,以IgM增高为主

D.EEG常见弥漫的θ和δ波,亦可见棘波和棘慢复合波

E.MRI可见脑和脊髓白质内散在多发的T1低信号、T2高信号病灶

题型:问答题

简述特别自首的概念和成立条件。

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