【题目】 I was watching the clock all through the meeting, as I had a train ______.
A.catching
B.caught
C.to catch
D.to be caught

【答案】C
【解析】句意：整个会议期间我在看钟，因为我有火车要赶。have something to do有某事要做，用不定式的主动式作定语，修饰a train。故选C。