根据加热温度和冷却方法的不同，热处理可分为哪些工艺？
参考答案：
退火、正火、淬火、回火等工艺。
Speaking of all the songs he has written, I think this is probably his ________ one.
A．better-known
B．well-known
C．best-known
D．most-known
技师在铸圈焙烧的低温阶段升温过快可能造成
A．铸造不全
B．冷隔
C．砂眼
D．气孔
E．铸件表面粗糙
