清扫集中联锁道岔时，未得到清扫道岔人员（）的汇报前，不得准备经过清扫道岔的进路。
A.上线作业
B.登记
C.下道避车
D.准备齐全
参考答案：C
Alice, you were supposed ________ your paper last Sunday. Why haven't you finished it yet?[ ]
A. to finishing
B. to have finished
C. finishing
D. having finished
用中文解释下面故障码的含义：0801（）；0B03（）；2502（）；“46”（）；Control voltage on（）；Dc link undervoltage（）；
