单项选择题
A.25mm B.30mm C.35mm D.40mm
A.2.5mm B.2.75mm C.3.0mm D.3.25mm
A.1.5t B.1.6t C.1.7t D.2t
A.（48±1）mm B.（49±1）mm C.（50±1）mm D.（52±1）mm
微信扫一扫,加关注免费搜题
