硅稳压管稳压电路中必须接限流电阻,因为稳压管稳压原理就是依靠稳压管的()电阻比限流电阻小得多来实现的。 ["静态","动态","负载","稳压"]
吊钩的危险断面磨损达原厚度的()应报废。 ["A.5%","B.10%","C.15%","D.20%"]
雨水泵站集水池的容积应大于最大一台水泵()的流量。 ["10s","20s","30s","40s"]
做碎石或卵石压碎值试验前不用剔除其针状和片状颗粒。()
电动机断相保护是一种电动机()保护。 ["断线","过载","短路","过压"]
试述螺纹的主要参数。