The moment I got home, I found I  ________my jacket on the

playground.                                                                           [ ]

A. had left                            

B. left

C. have left                          

D. was leaving

在数控机床上一次装夹中完成的工序内容，需考虑零件最后的（）要求。

A.尺寸

B.形状

C.位置

D.表面粗糙度

E.精度

F.热处理