It is not long before they are so accustomed to swimming that they can pick up

题目

It is not long before they are so accustomed to swimming that they can pick up
weights from the floor of the pool.
请问,it is not long before ,里面,long before是一个词组吗,我查了,是很久以前的意思,这样加一个not,就成什么了,不是很久以前,
然后,如果不按一个词组算,把它拆开,这样翻,它不是很长,在适应游泳以前,
这到底是怎么回事,应该怎么理解

答案

楼主的句子其实是两个句型的组合.第一个句型,It will not be / is not long+ before sb do,这其实是个时间状语从句,It will not be / is not long是主句,“（将）不会很久”的意思；before sb do是从句.句型的意思是...