单项选择题
A.0.25~0.80 B.0.25~0.60 C.0.30~0.65 D.0.35~0.70
A.0.25~0.80 B.0.10~0.50 C.0.15~0.65 D.0.20~0.70
A.热裂 B.开裂 C.热脆 D.裂纹