let sth be done and let sth done 的区别

题目

let sth be done and let sth done 的区别
既然过去分词本身能表被动为什么用原形BE呢,我不太明白,BE 在句中做什么成分.

答案

let sth be done is future tense [语法]将来时,something that will be happeninglet sth be done = leave it there,waiting for it to be done.等待去完成let sth done 基本上不用这个