如图所示,在x轴上方存在着垂直于纸面向里、磁感应强度为B的匀强磁场,一个不计重力

题型:选择题

问题:

如图所示,在x轴上方存在着垂直于纸面向里、磁感应强度为B的匀强磁场,一个不计重力的带电粒子从坐标原点O处以速度v进入磁场,粒子进人磁场时的速度方向垂直于磁场且与x轴正方向成120°角,若粒子穿过y轴正半轴后在磁场中到x轴的最大距离为a,则该粒子的比荷和所带电荷的正负是(  )

A.,正电荷

B.,正电荷

C.,负电荷

D.,负电荷

考点:带电粒子在匀强磁场中的运动
题型:选择题

       阅读下面短文,根据上下文和所给单词首字母,写出空白处单词正确形式。

      Mrs. Hill thought she came from a rich family and never did any (1)h            . Her husband (2)h           

to do all at home though he was (3)b             in his office. The man had to do some (4)s             in the

market on Saturday. Then he cooked for his family and then he did some (5)w            . When his wife went

to the dances, he began to read his books. He was polite and never (6)m             it at all. 

      It was a Sunday evening, Mrs. Hill made her husband go and see a new film with her. He had something

important to do and couldn't (7)a            . It made her (8)a             . She tore (撕) one of his expensive

dictionaries into (9)p            . Mr. Hill said nothing and put on his clothes and went out. She knew he was

going to his (10)o            . She brought the key to his car out of his (11)p              and (12)t             it away

over the wall. He slapped (掴) her face and left. The woman began to (13)c              sadly. The next morning

she went to see her father, a famous professor, and told him (14)w             had happened to her.

      "Tom slapped me on my face to insult (侮辱) you!" said the woman. "You should retaliate against (报复)

him."

      The old man knew his daughter (15)w            . He asked, "On (16)w             side of your face did he

slap you?"

     "On the left side."

      The professor slapped her on the right side of the face and said, "He's insulted my daughter and I had to

insult his (17)w            !" 

      Of course the woman knew what it (18)m             and she did nothing to provoke (招惹) her

(19)h             any (20)l            .

题型:选择题

如图所示,实线是某时刻的波形图,虚线是0.2 s后的波形图。

(1)若波向左传播,求它传播的最小距离。

(2)若波向右传播,求它的最大周期。

题型:选择题

我国在发射探月卫星“嫦蛾1号”之后,又成功地发射了“神舟7号”飞船,并由翟志刚成功地进行了太空漫步。设“嫦娥1号”绕月球运动的轨迹和“神舟7号”绕地球运动的轨迹都是圆,其轨道半径分别为r1、r2,周期分别为T1、T2,线速度分别为v1、v2,角速度分别为ω1、ω2向心加速度分别为a1、a2,月球和地球的质量分别为m1、m2则 (     )

A.

B.

C.

D.

题型:选择题

某患者FFA表现如下:19秒视网膜动脉充盈,24秒视网膜静脉层流,45秒视网膜静脉充盈完全,视盘高荧光,边界不清,表面毛细血管扩张,视网膜散在点状高荧光及大量荧光遮蔽区,静脉显著迂曲扩张,部分静脉管壁染色。周边视网膜无灌注区约20DD,晚期黄斑花瓣状高荧光。

患者最重要的治疗是()

A.糖皮质激素应用

B.全视网膜光凝

C.治疗原发病

D.纤溶制剂应用

E.血管扩张药物的应用

题型:选择题

(五)丁注册会计师负责对F公司2×10年度财务报表进行审计。在了解F公司内部控制时,遇到下列事项,请代为做出正确的专业判断。

在对被审计单位的控制活动的了解中,丁注册会计师注意到以下控制活动,其中属于实物控制活动的是( )。

A.对访问计算机程序和数据文件进行授权

B.出于特定原因,同意对某个不符合一般信用条件的客户赊销商品

C.分析评价实际业绩与预算的差异

D.将交易授权、交易记录以及资产保管等职责分配给不同员工

更多题库