什么是晶闸管(SCR)?
参考答案:
晶闸管(SCR)的全称为晶体闸流管,是一种可控大功率半导体电力电子器件,它包括普通晶闸管、双向晶闸管、可关断晶闸管及光控晶闸管。
Mr Smith was________to be a doctor but he became a teacher when he grew up.[ ]
A.demanded
B.supposed
C.suggested
D.agreed
如何实现对同一区域进行反复而精确的观测?