A.40 B.50 C.60 D.70
A.拉伸強(qiáng)度和延伸率低 B.溫度穩(wěn)定性較好 C.低溫不易脆裂 D.耐老化性較好
A.30 B.50 C.60 D.80
A.250mm/d B.500mm/d C.750mm/d D.1000mm/d
A.C20 B.C25 C.C30 D.C40