Finally he reached a lonely island was completely cut off from the outside world. A. when

问题补充：

Finally he reached a lonely island was completely cut off from the outside world.

A. when

B. where

C. which

D. whom

答案：

A. when

B. where

(答案→)C. which

D. whom

解析：句意为：最后他到达一个完全与世隔绝的孤岛。定语从句中缺少主语，因此使用关系代词；先行词island指物，故使用关系代词which.

【考点定位】考查定语从句