当工程车按首尾机车编组时，应使用首端机车驾驶，当首端机车故障而使用尾端机车驾驶时，按（）运行办理。
参考答案：推进
Jane was disappointed that most of the guests ______when she _______ at the party.
A．left; had arrived
B．left; arrived
C．had left; had arrived
D．had left; arrived
如果CDU故障,与此无关的显示是:（）
A、P1板上FMC灯亮
B、CDU黑屏
C、CDU上的按键无反应
D、CDU上的通告灯不亮
