A.5%~20% B.5%~10% C.15%~20% D.20%~30%
A.自潤(rùn)滑性能 B.相對(duì)摩擦系數(shù)小 C.耐摩擦性 D.耐沖擊性
A.80% B.65% C.70% D.75%