I 完形填空
阅读下面短文，掌握其大意，然后从21-30各题所给的A、B、C和D项中，选出最佳选项。
My mother used to ask me what is the most important part of the body. Through the years I would guess at what I thought was the correct answer.When I was younger，I thought__1__was very important to us as humans，so I said，“My ears，Mommy.” She said，“No.Many people are __2__.But you keep thinking about it and I will ask you again soon.”
Several years passed before she asked me again.Since making my first__3__，I had contemplated the correct answer.So this time I told her，“Mommy，sight is very important to everybody，so it must be our eyes.” She looked at me and said，“You are __4__ fast, but the answer is not correct because there are many people who are blind.”
Over the years, Mother asked me a couple more __5__ and always her answer was，“No, but you are getting___6__every year，my child.” Then last year，my Grandpa __7__.Everybody was heart broken，crying.My mom looked at me w hen it was our __8__ to say our final goodbye to Grandpa.She asked me，“Do you know the most important body part yet, my dear？”
