单项选择题
A.1.5mm B.3mm C.2.5mm D.1mm
A.3mm B.2.5mm C.1.5mm D.1mm
A.1mm B.1.5mm C.2.5mm D.3mm
A.T+(0~3) B.T+(3~6) C.t/2≤K≤t D.t/3≤K≤2t
微信扫一扫,加关注免费搜题