"know better than to do sth."结构随笔

在《大学英语》(李荫华主编,上海外语教育出版社出版)第四册第一单元中有这样一个句子:I had had a marvelous steak,but knew better by now than tosay so.这里的"know better than to do sth."是固定搭配,我们在阅读理解或翻译时,切莫望文生义,而应从语义和结构上去理解它。