题目普通高速钢的常温硬度约可达A. HRC40~45B. HRC50~55C. HRC60~65D. HRC70~75普通高速钢的常温硬度约可达A. HRC40~45B. HRC50~55C. HRC60~65D. HRC70~75题目解答答案C. HRC60~65