带电粒子以速度v从两平行金属板形成的匀强电场的正中间垂直电场射入,恰穿过电场而不

题型:选择题

问题:

带电粒子以速度v从两平行金属板形成的匀强电场的正中间垂直电场射入,恰穿过电场而不碰金属板,欲使入射速度为

v
2
的同一粒子也恰好穿过电场不碰金属板,则必须(  )

A.使粒子电量减为原来的

1
2

B.使两板间的电压减为原来的

1
4

C.使两板间的电压减为原来的

1
2

D.使两板间的距离减为原来的

1
2

考点:带电粒子在电场中运动的综合应用
题型:选择题
阅读下列材料及相关信息,从所给的六个选项(A、B、C、D、E、F)中,选出符合各小题要求的最佳选项。选项中有一项是多余选项。以下是演讲会的资料:
A
Are you interested in “Dream of the Red Mansion”(Hong Lou Men)? Listen to a lecture on this classical novel.
Venue: National Museum of Chinese Modern Literature (Beijing)
Time: 9:30 A.m.
Price: free
Tel: 010 – 84615522
B
“Jiaguwen” is among the oldest pictographic characters in the world.How much do you know about it? Get all the answers at this free lecture.
Venue: Dongcheng District Library (Beijing)
Time: 9:00 A.m.
Price: free
Tel: 010 – 64013356
C
Former United Nations interpreter Professor Wang Ruojin speaks about her experiences at the UN and shares her understanding of the cultural differences between East and West.
Venue: National Library of China (Beijing)
Time: 1:30 p.m. – 4:00 p. m.
Price: free
Tel: 010 – 68488047
D
Qi Baishi, one of China’s greatest modern painters, was also a poet, calligrapher(书法家) and seal-cutter(刻印者). Can you appreciate his works? Then come to spend the time with us.
Venue: Beijing Art Academy
Time: 9:00 A.m. – 11:00 A.m.
Price: 10 yuan
Tel: 010 - 65023390
E
It is the year of the Dog, and you can see “Fu” everywhere. But how much do you know about dogs – man’s best friend? What is “Fu” and where does it come from? Why do people hang “Fu” character upside down on the door? Get all the answers from this free lecture.
Venue: Capital Library (Beijing)
Time: 2:00 p. m.
Price: free
Tel: 010 - 67358114
F
About 160 cultural relics from Guangdong, Macao and Hong Kong are on display to April 15th. Meanwhile experts will talk about the important roles these three cities have played in the past two thousand years of Sino–Western exchanges.
Venue: Beijing Art Museum
Time: 2:00 p. m. – 5:00 p. m.
Price: 20 yuan, students 10 yuan
Tel: 010 - 83659337
 
以下是想去听演讲的人员的基本信息,请匹配适合他们的演讲内容。
1. Alice is now studying in Beijing University, and she is especially interested in Chinese writing. In her spare time she enjoys drawing, writing poems and is fond of sharing her pieces with her classmates.
2. Simon comes from Egypt. He is now studying in Beijing Art Academy. He shows great interest in Chinese ancient characters. Now he wants to know much about it.
3. Lora and Peter, visiting professors from Australia, are both crazy about Chinese traditional culture. At weekends they like to call on Chinese families to learn about Chinese festivals as well as their history.
4. Edward is a senior student in Beijing Foreign Language University. He likes traveling very much and has made up his mind to work as an interpreter for some joint–venture enterprises (合资企业).
5. Steve and Mark are both studying in the Chinese Department of China’s Renmin University. They want to do some research on Chinese ancient literature.
题型:选择题

一个长方体的棱长总和是72厘米,它的长、宽、高的比是4:3:2,它的表面积是______平方厘米,它的体积是______平方厘米.

题型:选择题

讲授法

题型:选择题

下列哪一项不属于医德意识现象()。

A.医德观念

B.医德情感

C.医德信念

D.医德意志

E.医德评价

题型:选择题

员工内部下岗期间,应参加业务培训或跟班劳动,但不得担任()重要工作。

A、工作许可人、工作负责人等

B、工作监护人、工作负责人等

C、工作监护人、工作许可人等

D、工作负责人、工作班成员

更多题库