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问题 选择题

图中通电螺线管磁极的极性标注正确的是

答案

答案：C

A、电流由螺旋管的左端流入，由安培定则可知，螺旋管的左端为N极，故A错误，不符合题意．

B、电流由螺旋管的右端流入，由安培定则可知，螺旋管的右端为N极，故B错误，不符合题意．

C、电流由螺旋管的右端流入，由安培定则可知，螺旋管的左端为N极，故C正确，符合题意．

D、电流由螺旋管的右端流入，由安培定则可知，螺旋管的左端为N极，故D错误，不符合题意．

单项选择题

E


Last year, Shanghai-born Charles K. Kao and two North American scientists got the 2009 Nobel Prize(诺贝尔奖) in Physics together. Their work made the Internet come into a new age.
Kao, 77, was born in Shanghai in 1933. He is famous for finding out how to transmit (传输)light signals(信号) over long ways through glass fibers (玻璃纤维) as thin as a human hair. His work makes the Internet information transmit faster around the world. Kao was vice chancellor(副校长) of the Chinese University of Hong Kong from 1987 to 1996. He doesn’t work, and lives in Hong Kong now.
The Chinese people were pleased to learn the good news. "The people of Hong Kong and I send our congratulations to Kao on receiving the prize... Kao is also a true gentleman. We are greatly proud to have such an excellent person in Hong Kong. "Zeng Yinquan once said.
Willard Boyle, a Canadian American, and George Smith of the United States got the other half of the prize.

Which of the following is Not true ( )

A．Kao’s work makes the Internet information transmit faster around the world.

B．Kao is still working in the Chinese University of Hong Kong now.

C．Willard Boyle and George Smith are both scientists.

D．Kao is died now.
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填空题

对象是既包含数据又包含对______的方法，并将其封装起来的一个逻辑实体。
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