单项选择题
A.30° B.50° C.55° D.60°
A.失去流动性 B.杂质多少 C.发热量高低 D.挥发分高低
A.0.25%~0.6% B.2.11%~6.69% C.0.6%~1.3% D.1.3%~2.11%