A.KW B.HU C.W D.L E.CM
A.螺距2和螺距1相等 B.螺距2是螺距1的1.5倍 C.螺距2是螺距1的2倍 D.螺距2是螺距1的0.75倍 E.螺距1是螺距2的2倍
A.45~55HU B.0~20HU C.75~100HU D.100~130HU E.-30~0HU