当只考虑复杂电路中某一条支路电流电压的情况，采用哪种计算方法比较方便？
参考答案：戴维定理
下列可引起停经后 * * 出血的疾病有
A．无排卵性功血
B．异位妊娠
C．葡萄胎
D．不全流产
E．子宫内膜癌
In spite of these unexpected difficulties, but the Chinese scientists __________ to carry out their
experiments on the lonely island. [ ]
A. threatened
B. managed
C. offered
D. hesitated
