You should make it a rule to leave things you can find them again. A. whenB. whereC. then

问题补充：

You should make it a rule to leave things you can find them again.

A. when

B. where

C. then

D. which

答案：

A. when

(答案→)B. where

C. then

D. which

解析：考查定语从句。你应该放置东西有一个规则，这样你能在那儿再次找到他们。前文为从句的逻辑地点状语，故引导词用where。选A。