单项选择题
A.3 B.4 C.5 D.10
A.1/2 B.3/5 C.3/4 D.2/3
A.0.5mm B.1mm C.2mm D.2.5mm
A.5mm B.10mm C.15mm D.20mm
微信扫一扫,加关注免费搜题