递动杆头部长度超过7．0mm时更换，制动安定保压试验发生自然缓解时，可在限度内调长递动杆。
参考答案：对
To learn English well, we should find opportunities to hear English _____ as much as we can.
A．speak
B．speaking
C．spoken
D．to speak
沪西一百店有一自动扶梯，某顾客沿开动（上行）的自动扶梯走上楼时，数得走了N1级；当他以同样的速度（相对电梯）沿开动（上行）的自动扶梯走下楼时，数得走了N2级，则自动扶梯静止时该自动扶梯级数为______级．
