7．by不迟于.到--为止 [用法]by表示“不迟于某时 .“在某时之前 .常与完成时态连用,若指“到过去的某一时候止 .则用过去完成时,有时by后接将来时间.也用将来时. [举例](1) Perhaps she has recovered by now.或许到现在她已康复了. (2) By next Friday I ought to have finished the job. 到下周五.我应完成这项工作. (3)By the end of last term.We had studied more than five hundred English words．到上学期末为止.我们已经学了500多英语单词. (4) Your son will be all right by supper time.你儿子到晚饭时会好的. 【查看更多】
