阅读下面的故事，在结尾的横线处加一句话，使故事更加连贯完整

一个家里很穷的年轻人，和母亲生活在一起。年轻人对母亲的辛勤劳作不以为意，自己也不屑劳作，却一心向佛。为了追求他心中的佛，年轻人千里迢迢到寺院里向老方丈探寻佛的真谛。老方丈告诉年轻人，肯为你光脚开门的人，就是你欲找的佛。

年轻人开始了漫漫的寻佛征途。他路过许多寨子，投宿了不少村庄。年复一年，大多数时候他都被别人视为龌龊的乞丐而撵出门。年轻人对佛的追求开始动摇。他开始无比想念自己的家，想念自己不辞而别的母亲。

一天深夜，年轻人回到了家，轻轻呼一声：“娘！”门便开了，母亲没有一声抱怨地说道：“我的儿，你可回来了！”

年轻人看到了　　　　　　　　　　　　　　　　　　　　　。

The process of gaining or losing weight can be explained by comparing your body to your car. Both run (51) fuel, food for your body and gasoline for your car. Both (52) that fuel, first into heat, then energy, some of (53) is used to do work, and some emitted as waste. And (54) your car uses more energy when the engine is racing than when it is idling, (55) does your body use more energy when you are working hard than (56) you are resting.

For the purpose of this comparison, (57) , there is one significant difference between them. Your car cannot store fuel by turning it into (58) else; all gasoline not (59) remains as gasoline. But your body stores (60) energy as fat. When the gas tank is completely empty, the car won’t run; but your body can burn fat to provide more energy.

53().

A.what 

B.which 

C.it 

D.them