三相半波整流电路中,3只二极管均接反,整流电路将变成()。
A.单相半波电路
B.三相半波电路
C.断路
D.短路
参考答案:B
The waiter hardly has a day off, ? [ ]
A. hasn't he
B. doesn't he
C. will he
D. does he
“寒生热,热生寒”体现的理论依据是
A.阴阳的对立制约B.阴阳的互根互用C.阴阳的消长平衡D.阴阳的相互转换