制动器效能因素
参考答案：
在制动鼓或者制动盘的作用半径R上所得到的摩擦力（Μμ/R）与输入力F之比
成煤的控制因素有哪些？
A．A change in French eating habits.
B．A boom in long-hour meals in France.
C．The origin of hamburgers.
D．The home of the sit-down mid-day meal.
