An old gentleman whose eyesight was failing came to stay in a hotel room with a bottle of wine in each hand。On the wall there was a fly which he took for a nail。So the moment he hung them on，the bottles fell broken and the wine spilt all over the floor。
When a waitress discovered what had happened，she showed deep sympathy for him and decided to do him a favor。
So the next morning when he was out taking a walk in the roof garden，she hammered a nail exactly where the fly had stayed。
Now the old man entered his room。The smell of the spilt wine reminded him of the accident。When he looked up at the wall，he found the fly was there again！He walked to it carefully and slapped it with all his strength。
On hearing a loud cry，the kindhearted waitress rushed in。To her great surprise，the poor old man was there sitting on the floor，his teeth clenched and his right hand bleeding！
钉子还是苍蝇
一位视力正在衰退的老绅士住进了一家旅馆的客房。他双手各拿一瓶酒。在墙上有只苍蝇，他误以为是枚钉子。他把两只瓶子朝上一挂，瓶子掉下来摔碎了，酒洒了一地。
一个女服务员发现发生的事情以后，对他深表同情，决定帮他个忙。
于是，第二天早上他到楼顶花园散步时，她把一枚钉子钉在了苍蝇停过的地方。
此时老人回到了房里。倒洒的酒味让他想起了那件事。他抬头往墙上一看，苍蝇又停在了那儿！他轻手轻脚地走近，使尽全力拍了一掌。
听到一声大叫，好心的女服务员冲进房来。让她大为吃惊的是，可怜的老头正坐在地板上，牙关紧咬，右手滴血不止。
spilt[spil]vt。＆vi。溢出；泼出
例：The coflee is so full that it might spill over。咖啡太满可能会溢出来。
favor[feiv]n。好感，宠爱，关切，欢心，好意，喜爱vt。支持，赞成，照顾，促成，喜欢，证实，赐予
例：Would you please do me a favor？帮我个忙，好吗？
hammer[hm]vt。＆vi。锤打vt。击败
例：We hammered a team。我们击败了一支队伍。
slap[slp]vt。＆vi。掌击；拍打
例：The waves slapped against the boat。波浪拍打着小船。
clench[klent]vt。紧握，抓紧，咬紧
例：She clenched her teeth and refused to move。她咬紧牙关不肯挪动一步。
a fly in the ointment意为“美中不足”，如：I like the house，but there is a fly in the ointment-I have to commute so far to work。（我喜欢那套房子，但美中不足的是离上班的地方太远。）
fly by night意为“不可靠”，fly by night意为“在漆黑夜里飞行”吗？当然不能这样望文生义。不过，fly by night（不可靠）倒真的与夜晚行动有关――赖账房客为逃房租，夜晚偷逃出房东家。
19世纪早期，fly by night被用来形容“赖账的房客”――因为没钱付房租，他们只好在半夜偷偷逃走。很明显，fly在这里表示“逃离，逃跑”。随着时间的推移，fly by night的词义范围有所扩大，可表示任何不光明的行为，特别指那种犯下恶行后逃之夭夭的犯罪分子。
值得一提的是，在19世纪，fly也可指“一种只有两个轮子的轻型（出租）马车”。这种马车最初由一个车夫来驾驶，后来改为由马拉。
今天，我们常用flybynight来形容某个商人“不可靠，不可信任”，所以，做生意或搞投资千万别找那些flybynight company（无信誉的公司）来做自己的商业伙伴。如：I want a reputable tour operator，not one of these flybynight outfits。（我想找一家信誉好的旅行社，而不是那些靠不住的公司。）