风机的辅助设备包括哪些？
参考答案：
风机的辅助设备包括：进气管路系统、出气和排气管路系统、润滑系统、冷却系统、电气系统、仪控系统，有些还有动力系统等。
电梯的曳引机是（）。
A.是驱动电梯运行的动力装置
B.电动机、制动器和减速齿轮箱组成，靠曳引钢丝绳与曳引轮的摩擦来实现轿厢运动的驱动器
C.是一种使快速电动机与曳引绳传动机构的旋转频率协调一致的机械
D.当轿厢运行速度达到限定值时，能发出电信号并产生机构动作的安全装置
I ______ basketball with him yesterday afternoon. He did much better than me. [ ]
A. was playing
B. played
C. would play
D. had played
