内服吐风痰,外用灭虱杀虫的药为
A.胆矾B.常山C.瓜蒂D.藜芦
参考答案:D
She needs ________ after her mother. [ ]
A. look
B. to look
C. looking
D. looks
A.时刻t线圈中电流的瞬时值icosωt
B.线圈中电流的有效值I
C.线圈中电流的有效值I=
D.线圈消耗的电功率P