选用材料Cr12MoV制作冲裁模凸模,其热处理硬度要求达到()
A.28~32HRC
B.38~42HRC
C.48~52HRC
D.58~62HRC
参考答案:D
—What do you think of living______ in a big flat?
—I think I will feel______. [ ]
A. on your own; alone
B. by yourself; lonely
C. alone; by yourself
D. lonely; alone
电压的单位为(),电流的单位为(),电阻的单位为()