All things (had) been canceled (because) of the snowstorm, many passengers could do (nothing) but (take) the train.
【正确答案】 A
【答案解析】本题中已有谓语动词could do，所以逗号前半部分应用非谓语动词形式，非谓语动词与逻辑主语all things之间是主动关系，用现在分词形式，所以应改为having been canceled。