读者提供的两个A都很有趣，因为英文的很多俏皮话很难翻译，我试着意译一下，让大家欣赏一下人家的科学QA：

Q：我爸老教训我，不让我挖鼻孔，更不让我吃鼻涕嘎巴儿。请问，吃自己的鼻涕嘎巴儿有碍健康吗？

A1：

挖和吃这两个词比较适合用在牙买加黄山药身上。即使你的鼻涕嘎巴儿对你的健康无害，也会对你的人际关系有害，所以我建议你还是改嚼口香糖得了。

从生理学角度讲，吃风干鼻涕没啥害处。假设你嚼得很起劲的那块鼻涕嘎巴儿没有完全被风干的话，它也会通过你的咽喉，进入你的胃部。当然了，除非你用卫生纸把它擤出来，或者用手指悄悄涂在椅子的下面。

鼻涕嘎巴儿里生活的绝大部分细菌都是无害的。它们会被你的胃液烧死，尸体被消化吸收。但是，很可能会有少量顽强的细菌是有害的，而空气中的有毒物质也会附着在鼻涕嘎巴儿上，所以还是别吃的好。

换个角度想想，你之所以进化出鼻毛，挡住小虫子和细菌，显然是有用的。虽然擤鼻涕不能完全挡住细菌通过鼻腔进入你的消化道，但也总比你狂吃鼻涕嘎巴儿强。

Jon Richfield, 南非

Who nose?

Q：My dad keeps telling me not to pick my nose and eat it. Will eating my bogeys [boogers] do me any harm?

A1：Picking and eating are for cherries. Even if your bogeys do not affect your digestion, chewing them could affect the health of your social relationships. Try chewing gum instead.

Physiologically, eating your dried snot would not matter much. If that solid bogey that you find so toothsome had not dried out, it would have dribbled down your pharynx and been swallowed anyway, unless you intercepted it with your sleeve or handkerchief or stuck it on the underside of your chair.

For the most part, any germs it contained would be digestible or would otherwise die in your gut, but this is not always the case. Some germs do infect people via the nose, and some toxic dust particles do stick in your phlegm and it is to the benefit of your health to ensure you expel such things.

It is not for nothing that your nose hairs stop bugs and dust from landing in your lungs or gut. Blowing your nose would not stop everything, but it is better than guzzling snot.

Jon Richfield, Somerset West, South Africa  ”