A.10.0 B.17.0 C.25.0 D.50.0
单项选择题金属材料弯曲试验,采用支辊式弯曲装置,支辊内侧距为()
A.D+2.5d B.D+3d C.(D+3d)±0.5d D.(D+2.5d)±0.5d