单选题 I had been sitting in my seat for at least two hours, waiting ______.
A. the train to start B. for the train starting
C. for the train to start D. for the train start

【正确答案】 C

【答案解析】[解析] 本题考查非谓语动词。此处用现在分词做状语，表示伴随的动作。wait for...意为“等待……”是固定搭配，其后start用不定式表目的和状态发展的趋势。