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问题 单项选择题

在19世纪上半期，欧洲流行着这样的说法：“史蒂姆（Steam，即蒸汽机）是英国人。”对这句话的准确理解是（）。①当时使用蒸汽机的都是英国人②以蒸汽为动力的机器是英国发明的③当时的英国已广泛使用蒸汽机④蒸汽机是英国工业革命的标志性成就

A.①②

B.①③

C.②④

D.③④

答案

参考答案：D

多选题
如图所示，理想变压器原线圈接u=220sin100πt （V）的 正弦交流电源，图中电流表内阻不计．副线圈接入“110V，60W”灯泡一只，且灯光正常发光．下列说法正确的是（   ）

A．电流表的示数为3/11 A

B．通过灯泡的电流的频率为50Hz

C．电流表的示数为3/22 A

D．理想变压器原、副线圈匝数之比为2:1

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单项选择题

Man: My brother is coming this weekend, and I was thinking the three of us could go out to dinner Saturday night. Any suggestionsWoman: It's up to you. I don't know the restaurants here that well.Question: What does the woman mean

A．She can make a reservation at the restaurant.

B．The man should decide where to eat.

C．She already has plans for Saturday night.

D．The man should ask his brother for suggestions.
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