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问题 单项选择题

移动通信基站所在地区土壤电阻率低于（）时，基站地网的工频接地电阻宜控制在10Ω以内。

A.400Ω.m

B.500Ω.m

C.600Ω.m

D.700Ω.m

答案

参考答案：D

单项选择题

The software architecture of a program or computing system is the structure or structures of the system, which comprise software ______, the externally ______properties of those components, and the relationships between them.The architecture is not the operational software. Rather, it is a ______ that enables a software engineer to: analyze the ______ of the design in meeting its stated requirements, consider architectural alternatives at a stage when making design changes is still relatively easy, and reduce the ______ associated with the construction of the software.

A. visibleB. reliable C. secure D. robust
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问答题 简答题

送电线路的拉线有哪几种？
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