一般来说，二段球磨机中粗级别物料的含量随着其分级返矿量的增加而（）
A.减少
B.增加
C.不变
参考答案：B
---I'll be away on a business trip .Would you mind looking after my cat?
---Not at all.____________.
A．I've no time
B．I'd rather not
C．I'd like
D．I'd be happy to
