什么是正弦交流电的三要素?
参考答案:
正弦交流电的三要素是:①最大值;②频率;③初相角。
— What's the matter?
— I am having trouble ______ who has taken my book. [ ]
A.finding
B.looking for
C.finding out
D.looking up
下列不属于温补学派的医家是
A.薛立斋
B.赵献可
C.绮石
D.李中梓
E.孙一奎