You should make a rule to leave things you can find them easily.A. it; whereB. it; thenC.

问题补充：

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

A. it; where

B. it; then

C. that; there

D. this; when

答案：

(答案→)A. it; where

B. it; then

C. that; there

D. this; when

解析：考查代词及状语从句。句中it作形式宾语，真正宾语为to leave things where you can find them easily；where引导地点状语从句，选A。