单项选择题
A.堆焊 B.镀铬 C.粘结 D.金属扣合法
A.102.36mm,56.17mm B.115.40mm,53.80mm C.77.60mm,48.20mm D.108.03mm,52.02mm
A.40m/s B.40m/min C.400m/min D.19.782m/min