设空间存在竖直向下的匀强电场和垂直于纸面向里的匀强磁场,如图所示,已知一离子在电

题型:不定项选择

问题:

设空间存在竖直向下的匀强电场和垂直于纸面向里的匀强磁场,如图所示,已知一离子在电场力和洛伦兹力的作用下,从静止开始自A点沿曲线ACB运动,到达B点时速度为零,C点是运动的最低点,忽略重力,以下说法正确的是

[ ]

A.离子必带正电荷

B.A点和B点位于同一高度

C.离子在C点时速度最大

D.离子到达B点时,将沿原曲线返回A点

考点:带电粒子在复合场中的运动
题型:不定项选择

我国修改后的民事诉讼法于2013年()起施行。

A.1月1日

B.5月1日

C.7月1日

D.6月1日

题型:不定项选择

在下列有关账项核对中,不属于账账核对的内容是( )。

A.总账账户贷方余额合计与其明细账贷方余额合计的核对

B.银行存款日记账余额与其总账余额的核对

C.总账账户借方发生额合计与其明细账借方发生额合计的核对

D.银行存款日记账余额与银行对账单余额的核对

题型:不定项选择

氧气瓶和乙炔瓶工作间距不应少于多少米?()

A、3米

B、4米

C、5米

D、1米

题型:不定项选择

会议电话分机使用的电源为()两用。

题型:不定项选择

Most people have no idea of the hard work. One of the questions that is always asked of me is (1) I became an animal collector in the first (2) .The answer is that I have always been interested in animals and zoos. According to my parents, the first word I was able to say with any (3) was not the conventional "mamma" or "daddy", (4) the word "zoo", which I would (5) over and over again with a shrill (6) until someone, in order to (7) me up, would take me to the zoo. When I (8) a little older, we lived in Greece and I had a great (9) of pets, ranging from owls to seahorses, and I spent all my spare time (10) the countryside in search of fresh specimens to (11) to my collection of pets.(12) on I went for a year to the City Zoo, as a student (13) , to get experience of the large animals, such as lions, bears, bison and ostriches, (14) were not easy to keep at home. When I left, I (15) had enough money of my own to be able to (16) my first trip and I have been going (17) ever since then. Though a collector’s job is not an easy one and is full of (18) , it is certainly a job which will appeal (19) all those who love animals and(20) .

第(18)空应选择()

A.expectations

B.sorrows

C.excitement

D.disappointments

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