冲裁间隙是一个很重要的工艺参数,它对冲裁件的()等均有较大影响。
A.压力均匀
B.模具寿命
C.断面质量
D.尺寸精度
E.冲裁力
参考答案:B, C, D, E
John's success has nothing to do with good luck. It is years of hard work _____ has made him what he is today. [ ]
A. why
B. when
C. which
D. that
层积云共分为()类。
A.5
B.6
C.7
D.8