问题
单项选择题
电子设备的接地母线可以采用薄铜排,当f≥1MHz时,其规格为( )。
A.0.35×160mm2
B.0.35×120mm2
C.0.35×10mm2
D.0.35×80mm2
答案
参考答案:B
电子设备的接地母线可以采用薄铜排,当f≥1MHz时,其规格为( )。
A.0.35×160mm2
B.0.35×120mm2
C.0.35×10mm2
D.0.35×80mm2
参考答案:B
阅读理解。 | |
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1. Mary likes (喜欢) _____. | |
A. red B. green C. blue D. black | |
2. The girl's last name is _____. | |
A. Green B. Mary C. red D. yellow | |
3. The boy's first name is _____. | |
A. Green B. Black C. Mary D. Jim | |
4. Jim's telephone number is _____. | |
A. 894-2015 B. 873-3516 C. 894-3516 D. 837 2015 | |
5. The two kids (小孩) are on line (在网上) _____. | |
A. at night B. in the evening C. in the afternoon D. in the morning |