单项选择题
A.2%;1% B.3%;1% C.2%;0.5% D.3%;0%
A.≥0.7mm B.≥0.4mm C.≥0.3mm D.0.3~0.7mm
A.≥250g/m2 B.≥300g/m2 C.≥200g/m2 D.200~400g/m2