题目

People aren’t walking any more——if they can figure out a way to avoid it. I felt superior about this matter until the other day I took my car to mail a small parcel. The journey is a matter of 281 steps. But I used the car. And I wasn’t in any hurry, either. I had merely become one more victim of a national sickness: motorosis. It is an illness to which I had thought myself immune ,for I was born in the tradition of going to places on my own two legs. At that time, we regarded 25 miles as good day's walk and the ability to cover such  a distance in ten hours as sign of strength抽取消化管某一部位的成分进行化验，发现含有淀粉、麦芽糖、脂肪，而蛋白质已经被初步消化，请问抽取的哪个部位（　　） A、口腔B、胃C、小肠D、大肠