单选题 No sooner had they got off the train ______ it started moving.
【正确答案】 B
【答案解析】[解析] 火车在他们刚下车的时候就发动了。
本题考查固定搭配。no sooner...than为固定搭配，意为“一…就…”，相当于hardly/scarcely...when...故选B。