计量泵属于往复式容积泵，也称定量泵或（）。
A、调节泵
B、离心泵
C、螺杆泵
D、比例泵
参考答案：D
— do you play basketball in school?
—Twice a week. [ ]
A. How long
B. How much
C. How many
D. How often
如何理解道德范畴信用与经济范畴信用的关系？
