【正确答案】
C
【答案解析】[听力原文] Ever lose your ability to taste during a cold, because your nose is stuffed up? That's because the nose is intimately involved with taste. When you chew, flavor compounds from the food may enter the back of your mouth. And when you breathe out, you carry some of those flavor compounds up into your nasal cavity. 'As children we basically learn, the first lesson of table manners is to keep the mouth closed while chewing, and you also want to breathe smoothly. ' Randy, a mechanical engineer at Penn State said, 'I think this is not only because it's polite, but also because you can smell the food much better if you can breathe smoothly. ' Smell contributes to taste by this 'backdoor'. And it turns out our airways are particularly tuned to enhance that effect. Randy and his colleagues 3D-printed a model of a woman's airway. To track airflow, they mixed water with special particles and pumped it through the model, filming the results. They found that when you breathe in, that inward airflow actually forms a curtain at the back of your mouth, blocking food particles from getting into the lungs, which is a good thing. And when you breathe out, air swirls through that cavity in the back of the mouth, sweeping up those particles and delivering them right to the nasal cavity, where you can smell them. There is a way to destroy this well-tuned system: the effect's ruined if you're really huffing and puffing. Meaning if you're wolfing down your food, gasping for air, that breathing actually delivers more of those food molecules into your lungs and fewer into the nasal cavity. In other words, your mother was right all along: keep your mouth shut and don't wolf down your food. It'll cut the chances of choking, and enhance the taste of the meal. How does Randy explain children's first lesson of table manners? 听力原文中提到I think this is not only because it's polite，but also because you can smell the food much better if you can breathe smoothly. 由此可知，Randy认为孩提时代学到的餐桌礼仪——在咀嚼食物时嘴巴要紧闭，同时呼吸平稳——不仅仅是出于礼貌，也在于当你呼吸更顺畅的时候能更好地闻到食物的味道。故选项C为答案。选项B与听力原文内容相反，选项A和D未在听力原文中提及，均排除。