如图所示,一质量为m,带电量为-q,不计重力的粒子,从x轴上的P(a,0)点以速

题型:问答题

问题:

如图所示,一质量为m,带电量为-q,不计重力的粒子,从x轴上的P(a,0)点以速度大小为v,沿与x轴正方向成60°的方向射入第一象限内的匀强磁场中,并恰好垂直于y轴射出第一象限.求:

(1)匀强磁场的磁感应强度B;

(2)穿过第一象限的时间t.

考点:带电粒子在匀强磁场中的运动
题型:问答题

阅读理解

     John Denver, the writer and composer of Goodbye Again, is one of the best-known American folk

singers and song writers. He is a country boy by birth and still prefers the mountains of Colorado to the

big cities he has visited in his many travels. He was born as Henry John in Roswell, New Mexico on

December 31, 1943. He later changed his name to the simpler John Denver after his favourite big city,

Denver Colorado.

     When he was a student, he knew he wanted to be a folk singer and sang in coffee houses at night.

Later he became famous. His song Goodbye Again expresses his feelings about travelling and being

away from home.

1. John Denver is not just good at singing but good at __________.

A writing stories

B. traveling

C. writing books

D. creating(创作) songs

2. Denver Colorado is the name of __________.

A. a mountain

B. a singer

C. a city

D. a country boy

3. John Denver loved the beauty of his favourite place so much that he __________.

A. traveled there many times

B. changed his name after its name

C. hated city life

D. felt sorry not to live there

4. Which of the following shows the correct relationship between America (A), New Mexico (N) and

Roswell(R)?

A. A>N>R

B. A>R>N

C. N>A>R

D. R>N>A

5. John's song Goodbye Again tells about __________.

A. his love for mountains

B. his opinion about life

C. his love for music

D. his feelings on leaving home

题型:问答题

竹筒屋平面布局犹如一节节的竹子,形成此类平面的主要原因是()。

A.粤东地区人多地少,地价昂贵

B.当地气候炎热潮湿

C.竹筒屋具有良好的通风、采光

D.讲究风水,屋主怕漏财

题型:问答题

荀子《劝学》中的“青,             ”,后来演变为“青出于蓝而胜于蓝”;韩愈在《师说》中与此语意思相类似的话是“是故                                 ”。

题型:问答题

总时差指的是( )。

A.最早开工时间与最迟结束时间的差
B.在不影响总工期的前提下,可以利用的机动时间
C.完成工期的最大期望时间
D.最迟开工时间与最早结束时间的差

题型:问答题

A建材商城收购原木400立方米,税务机关认可的收购凭证上注明收购款20000元,该企业支付运输费800元,将该批原木送往B实木地板厂,委托B实木地板厂为A加工特制木地板用于销售,合同注明,A需支付B实木地板厂加工费和辅料费含增值税金额7020元,A企业提货时被代收代缴的消费税为( )。

A.1464.21元
B.1410.53元
C.1368.42元
D.1270.74元

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