情志不舒或愤怒伤肝，肝失条达，藏泄失常，冲任不调而患月经病者，治则为
A．疏肝养肝B．泻肝除湿C．滋阴养肝D．疏肝泻火E．疏肝解郁
参考答案：A
_____ some mammals came to live in the sea is not known. [ ]
A. Which
B. Since
C. Although
D. How
根轨迹在开环复数极点处的切线与正实轴的夹角称为（）。
A.起始角
B.终止角
C.入射角
D.反射角
