论文部分内容阅读
我们吃进肚里的食物,先要在口腔作初加工,这对食物消化有三项作用,第一,坚硬的牙齿就像一部粉碎机,细细咀嚼,把食物磨碎;第二,唾液像洒水机那
First of all, the hard teeth are like a shredder, chewing delicately and grinding the food. Second, the saliva Like a sprinkler