加工细长的轴类零件，采用中心架或跟刀架的目的是：（）
A.增强工件的刚性，减少变形
B.增强工件的硬度和耐磨性
C.增强刀具的强度和韧性
参考答案：A
It was ______ he does ______ makes his students enthusiastic about school.[ ]
A. that; that
B. what; what
C. that; what
D. what; that
下列各项中不属于变量组成部分的是( )。
A．变量名
B．变量属性
C．变量初值
D．变量大小
