具有引火下行作用的药物是（）。
A．肉桂
B．牛膝
C．地榆
D．栀子
参考答案：B
警察是执行国家专政职能的工具。 ( )
He is () drinker, who has been imbibing for so long that he has figuratively speaking, grown old with the vice.
A. an inveterate
B. an incorrigible
C. a chronic
D. an unconscionable
