夹紧机构用来把工件压紧，夹牢在（）。
A.史具体上
B.定位元件上
C.导向元件上
D.辅助元件上
参考答案：B
修改间隙补偿值是______。
A、改变刀偏值；
B、改变工件尺寸值；
C、补偿正反向误差值；
D、长度补偿。
No one appreciated his work during his lifetime, but________it is clear that he was a great artist.
A．in the aftermath
B．by the time
C．in retrospect
D．in this eventuality
