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。