单元制动机闸瓦上的力与制动缸活塞力之比称为制动率。
参考答案：错
When caught in the exam，he begged for my pardon and tried punishment.
A．cheating；escaping
B．cheating；to escape
C．to be cheating；escaping
D．to be cheating；to escape
再热蒸汽温度如何调整？
