钢材加热达到奥氏体化以后，以大于临界冷却速度快速冷却的工艺过程叫（）。
A．回火
B．正火
C．淬火
参考答案：C
The president has told his friends that he is sick but will not admit it _____.
A．in private
B．in secret
C．in public
D．in detail
柚木地板
