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问题 单项选择题

已知均匀磁场的磁感应强度B是0.8T，直导体的有效长度10cm导体在垂直于磁力线方向上运动的速度是V=10m/s，直导体上的感应电动势应为（）。

A、80V

B、8V

C、0.8V

D、0.08V

答案

参考答案：C

填空题

已知tanα=9.7340，则锐角α=______（精确到1′）．
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单项选择题

Many institutions of higher education suffer declining enrollments during periods of economic slowdown. At two-year community colleges, however, enrollment figures boom during these periods when many people have less money and there is more competition for jobs.
Each of the following, if true, helps to explain the enrollment increases in two-year community colleges described above EXCEPT （）.

A．During periods of economic slowdown, two-year community colleges are more likely than four-year colleges to prepare their students for the jobs that are still available.

B．During periods of economic prosperity, graduates of two-year community colleges often continue their studies at four-year colleges.

C．Tuition at most two-year community colleges is a fraction of that at four-year colleges.

D．Two-year community colleges devote more resources than do other colleges to attracting those students especially affected by economic slowdowns.

E．Students at two-year community colleges, but not those at most four-year colleges, can control the cost of their studies by choosing the number of courses they take each term.
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