单选题 Not until all the fish died in the lake ______ how serious the pollution was.
  • A.did the villagers realize
  • B.the villagers realized
  • C.the villagers did realize
  • D.didn't the villagers realize
【正确答案】 A
【答案解析】[解析] not until意为“直到…”。如果把它放在句首，句子要倒装，而D项的结构是对整句的又一次否定，也不符合句意。因此，只有did the villagers realize最合适。