单项选择题
A、螺栓联接、双头螺柱联接、螺钉联接、紧定螺钉联接 B、螺栓联接、双头螺柱联接、螺钉联接 C、双头螺柱联接、螺钉联接、紧定螺钉联接 D、螺栓联接、双头螺柱联接、紧定螺钉联接
A.500mm B.1000mm C.250mm D.2000mm
A.8mm B.16mm C.24mm D.40mm