The villagers dug many tunnels they could fight against the enemies. A. by whichB. throu

问题补充：

The villagers dug many tunnels they could fight against the enemies.

A. by which

B. through that

C. through which

D. to which

答案：

A. by which

B. through that

(答案→)C. through which

D. to which

解析：考查定语从句：句意：村民们挖了很多隧道通过这些隧道他们可以和敌人斗争。先行词是tunnels，定语从句中缺少的是through tunnels，用介词through+关系代词which引导定语从句，选C。