棒磨机内的磨矿介质是（）。
参考答案：钢棒
当归龙荟丸的功能是（）
A.润肠通便
B.泻火通便
C.理气通便
D.健脾益气，润肠通便
E.宽中理气，泻下通便
The passenger was very impolite to the conductor, ____ , of course , made things even worse.
A．who
B．whom
C．which
D．what
