As blind as a bat.看不清的;不易看清的;
As busy as a bee.忙碌的蜜蜂；
As sound as a bell ；健壮；
As fresh as a daisy.新鲜的菊花；
As slippery as an eel；滑如泥鳅；
As light as a feather; 轻如鸿毛；
As sly as a fox;像狐狸一样狡猾；
As old as the hills.极古老；
As quiet as a mouse.（像老鼠一样）不声不响；十分安静；
As stubborn as a mule；像骡子一样顽固；
至于为什么,那就由读者发挥想象力了吧.笔者实在不知.