Not until all the fish died in the river how serious the pollution was.A. the villagers d

问题补充：

Not until all the fish died in the river how serious the pollution was.

A. the villagers did realize

B. the villagers realized

C. did the villagers realize

D. didn’t the villagers realize

答案：

A. the villagers did realize

B. the villagers realized

(答案→)C. did the villagers realize

D. didn’t the villagers realize

解析：考查倒装句。否定词放在句首主句使用部分倒装，助动词提前，句意：直到河里所有的鱼都死了，村民们才意识到污染是多么的严重呀。根据语境选C。