变压器能否用熔断器保护?有什么要求?
参考答案:
变压器可选用熔断器保护,但其性能必须满足系统短路容量,灵敏度和选择性的要求。
We didn't get the Snoopy doll because they had been ______. [ ]
A. sold of
B. sold off
C. sold out
D. sold over
巷道中的水沟坡度应与巷道坡度相同,通常为()。
A.3~5%
B.3~5‰
C.3~5