下图是血液透析图，请分析回答：

听短文，写出所缺部分。

    Hi! My name is Linda! I'm a middle school student. It was____lastSunday．After breakfast, my grandparents went for a walk in the park with their dog．They liked the____air there．My father____with his friend．My mother had to____．What about my brother? He read a book about____in his room．I practiced the piano in the living room．

如图，点E、F、G、H分别为菱形A₁B₁C₁D₁各边的中点，连接A₁F、B₁G、C₁H、D₁E得四边形A₂B₂C₂D₂，以此类推得四边形A₃B₃C₃D₃…，若菱形A₁B₁C₁D₁的面积为S，则四边形A_nB_nC_nD_n的面积为____．