三相桥整流电路中,当控制角α在以下哪个范围时,电路工作在逆变状态?()
A.0<α<π/2
B.0<α<π
C.π/2<α<π
D.π<α<2π
参考答案:C
Look! Tom is too sleepy to work. He _____ up watching TV. [ ]
A. mustn't have stayed
B. shouldn't have stayed
C. mustn't stay
D. ought not to say.
在实际的教学中,有的教师对学生作业采用“漏一补十”“错一罚十”的做法。 问题:你怎样看待这一现象请运用记忆的有关规律加以分析。