A.0.1~0.2mm B.0.2~0.3mm C.0.3~0.4mm D.0.4~0.5mm
A.50~100mm B.100~150mm C.150~200mm D.200~250mm
A.潮濕 B.有銹蝕 C.有灰土 D.干燥無(wú)塵