单项选择题
A.5mm B.10mm C.15mm D.20mm
A.聚氯乙烯 B.聚乙烯 C.交联聚乙烯
A.1.94mm B.1.72mm C.1.96mm D.2.06mm
A.1.2mm B.1.4mm C.1.6mm D.1.8mm
微信扫一扫,加关注免费搜题