A.60m B.40m C.25m D.20m
A.50mm B.60mm C.75mm D.90mm
A.2對(duì) B.4對(duì) C.6對(duì) D.8對(duì)
A.3mm B.6mm C.9mm D.12mm
A.70m B.60m C.40m D.30m
A.拉應(yīng)力 B.壓應(yīng)力 C.剪應(yīng)力 D.拉應(yīng)力與壓應(yīng)力