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

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

A.was about to

B.was likely to

C.was supposed to

D.is due to

答案及解析： C

解析：

导解：A表示“正要、就要”；

B表示“可能”；

D表示“约定的”(时态不对)；

C表示“应该”，符合上下文意思及时态．