切削加工三要素是（），（）、（）。
参考答案：切削速度；进给量；吃刀深度
Dave lost his job and was short of money, so _____ his flat and move in with his brother. [ ]
A. that he did was to sell
B. what he did sell
C. what he did was to sell
D. what he did sold
我国的立法体制总体上看属于( )。
A．一元一级体制
B．一元多级体制
C．二元一级体制
D．二元多级体制
