钢的最高淬火硬度,只要取决于钢中()的含碳量、
A、贝氏体
B、奥氏体
C、渗碳体
参考答案:B
He has five _______. He plays _______ after school. [ ]
A. basketball; basketball
B. basketball; basketballs
C. basketballs; basketball
D. basketballs; basketballs
油机的曲轴连杆机构主要包括()等零件。
A、气缸
B、活塞
C、连杆
D、曲轴