单项选择题
A.20mm B.30mm C.50mm D.80mm
A.1倍 B.2~3倍 C.4~5倍 D.7~8倍
A.1cm B.2cm C.4cm D.紧贴,不要距离。
A.10mm B.5mm C.15mm D.2mm
微信扫一扫,加关注免费搜题