21.Cast pearls before swine对牛弹琴；白费好意
To Cast pearls before swine的意思是“珍珠头在猪猡前面”。
swine是个旧词,书面词,即今为pigs,不过swine单复同行,本句为复数。
这个成语源自《新约。马太福音》第7章:“Give not that which is holy unto the dogs,neither cast ye your pearls before swine,lest they trample them under their feet,and turn again and rend you”。由于to cast pearls efore swine,比喻确切,在后世不断引用中而成为一个国际性成语,常用来表示to offer sth valuable or beautiful to those who can't appreciate it；to give what is precious to those who are unable to understand its value等意思,含有轻蔑嘲笑色彩。按其字面意义,这个成语与汉语成语“明珠按投”相似,但是寓意不同,基本上不对应；按一比喻意义,它相当于“对牛弹琴”,“向驴说经”“一番好意给狗吃”“狗咬吕洞宾,不识好人心”等。
She read them Shakespeare,but it was casting pearls before swine
I won't waste good advice on John any more because he never listens to it.I won't cast pearls before swine.
……and when I let the upper floor to Cap'en Cuttle,oh i do a thankless thing,and cast pearls before swine
22.a wolf in sheep's clothing批着羊皮的狼；貌善心恶的人
耶稣在加利利一带传道布教,收了很多信徒。有一天,他对门徒说:"Beware of false prophets,which come to you in sheep's clothing,but inwardly they are ravening wolves"
eg:Mrs.Martin trusted the lawyer until she realized that he was a wolf in sheep's clothing
One who teaches morality and practises immorality is a wolf in lamb's skine
23.separate the sheep from the goats区别好坏,分清良莠
《新约。马太福音》记述:“And before him shall be gathered all nations:and he shall separate them one from another,as a shepherd divideth his sheep from the goats”
由于《圣经》的影响,sheep和goat在英语中的形象截然不同,前者比喻好人,后者比喻坏人。英语中有关goat的成语,大多贬义。如:to play the goat=play the fool（瞎胡闹）；to get sb's goat（触动肝火） ；等等。《圣经》说牧羊人要分辨绵羊和山羊,“把绵羊安置右边,山羊左边”。据说野山羊常混进羊群里,引诱绵羊,故牧养人必须把它们区分开来,以免混淆。
由此,人们用to separate the sheep from the goats这个成语,来比喻to separate the good from the wicked； to divide good or useful people from bad or useless
eg:We'll go through the list of members,and separate the sheep from the goats
Have faith in me,please.I can separate the sheep from the goats
