问题
单项选择题
国际电工委员会(IEC)规定的标称有效焦点尺寸表示方法是
A．0.5mm2
B．0.5mm
C．0.5cm
D．0.5cm2
E．0.5
答案
参考答案：E
解析：根据国际电工委员会(IEC)336号出版物(1982年)规定，标称有效焦点的尺寸用无量纲数字来表示。
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国际电工委员会(IEC)规定的标称有效焦点尺寸表示方法是
A．0.5mm2
B．0.5mm
C．0.5cm
D．0.5cm2
E．0.5
参考答案：E
解析：根据国际电工委员会(IEC)336号出版物(1982年)规定，标称有效焦点的尺寸用无量纲数字来表示。
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| Last Saturday, Tony went to see Benny. But he didn't know 1 Benny lived. 2 the way, he stopped in front of a yellow house, and asked an old woman the 3 to Benny's house."His house is not far from my house," said the woman. "It's behind the trees. But you can't get there 4 .You can go there by bus. It'll 5 you hours to get there 6 foot.""What's 7 with her?" Tony thought."I can see Benny's house from here now. It's behind the 8 ." Then Tony walked to the other side of the trees. He found the old woman was 9 . There was a river in front of him, and he couldn't see a boat. The house was on the other side of the 10 . | ||||
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