接触网作业车由柴油机、电气系统、传动系统、制动系统、走行部、车体、液压系统及液压升降回转（）等组成。
参考答案：作业平台
A passenger train ________ about 1,500 people fell into the river when the bridge collapsed.[ ]
A. carrying
B. carried
C. to be carried
D. to carry
