国家对部分重点中药材购销实行管理，下列属于第一类的为（）
A.三七
B.人参
C.牛黄
D.甘草
E.黄连
参考答案：D
--Mr. Black, this is our language lab. Would you like to go in and have a look?
--OK.________.
A．Help yourself
B．This way, please
C．Follow me
D．After you
葡甘露聚糖
