采用半波整流方式进行直流耐压试验时，通常应将整流硅堆的负极接至试品高压端。
参考答案：错
He ______ in Shanghai University for four years before he ______ Beijing.
A．studied, had gone
B．had studied, went
C．has studied, goes
D．had studied, had gone
生产经营单位主要负责人的职责不包括( )。
A．督促、检查本单位的安全生产工作，及时消除生产安全事故隐患
B．组织制定并实施本单位的生产安全事故应急救援预案
C．及时、如实报告生产安全事故
D．做好有关安全生产工作
