磨机内钢球运转的条件是（）。
A.离心力大于等于重力
B.离心力小于重力
C.与离心力、重力无关
D.只与重力有关
参考答案：A
I do hope so because I want you to live ________ as I have.
A．as long and healthy a life
B．as a long and healthy life
C．as long and a healthy life
D．so long and healthy a life
消除离心泵的气蚀现象有哪些方法？
