对于位置闭环伺服系统数控机床,其位置精度主要取决于()。
A、机床机械结构的精度
B、驱动装置的精度
C、位置检测元件的精度
D、计算机的运算速度
参考答案:C
The chairman requested that ___________.
A.the members studied the problem more carefully
B.the problems were more carefully studied
C.the problems could be studied with more care
D.the members study the problem more carefully
根据污染物的排放方式,湖泊水库的污染源控制可以分为点源污染控制和面源污染源。