当离心压缩机转速不变，而流量指示变大，说明（）。
A、气体密度上升
B、气体密度下降
C、气体密度不变
D、关系难以确定
参考答案：B
Although this medicine can cure you your illness, it has a bad effect____you.
A．for; in
B．for; on
C．of; on
D．of; at
