单选题 All flights______because of the heavy snow, we had to take the train.
  • A) were canceled
  • B) had been canceled
  • C) have been canceled
  • D) having been canceled


【正确答案】 D
【答案解析】[解析] 本题考查非谓语动词。观察句子可知，这两个句子不是并列的分句，也不能构成复合句，后边是一个完整的句子，所以前边就应该用非谓语动词构成一个短语，在这里表原因，故选D。 [知识拓展] 现在分词的完成式表示该动作发生在主句的动作之前。