let up on的用法和样例：
例句
- He refused to let up on the boy until his school grades improved.
直到那孩子学业有了进步他才肯放宽他对他的管束。
let up on的相关资料：
临近单词
Lethe
let
Let's take a picture together?
Let's meet again on-line soon.
Let's go boating this afternoon.
Let' s forget our disagreements.
Let's have a three-course meal.
Let Every Student Study Effectually
Let there be no misunderstanding.
Let us take everything seriously.
Let's go downtown this afternoon.
Let's meet each other half-way.
