The train?to arrive at 11:30,but it was an hour late．

The train?to arrive at 11:30,but it was an hour late．
A、was supposed
B、is supposed
C、Supposes
D、supposed
【正确答案】：A
【题目解析】：【考情点拨】考查固定短语。 【应试指导】句意：那趟火车应该十一点半到，但是它晚了一个小时。be supposed to do sth．意为“应该做某事”，又因为本句时态为一般过去时，故选A。