在区间乘降所错误通过，定（）单位责任。
A、车长
B、机务
C、值班员
D、调度
参考答案：B
在地球表面附近，质量为1KG的物体受到的重力为（）实际质量。
A、9.8N
B、8.5N
---What did the policeman say to you just now?
--- He asked _______ when the accident happened.
A．what I was doing
B．what was I doing
C．what I am doing
D．what am I doing
