具有温肾阳，引火归原作用的药物是（）
A.附子
B.肉桂
C.肉苁蓉
D.牛膝
E.细辛
参考答案：B
— Lucy doesn't mind lending you her dictionary.
— She . I've already borrowed one. [ ]
A．mustn't
B．needn't
C．shouldn't
D．can't
简述潮汐的成因？
