题目

the difficulty is that by the time children reach school age, there are so many other influences that it is almost impossible to tell whether girls are worse at science and maths.
请分析一下句子.主句是哪个?that it is almost impossible to tell whether girls are worse at science and maths这个句子是什么从句?我真的是搞不懂了!

提问时间：2020-08-11

答案

主句是It is almost impossible to tell whether girls are worse at science and maths
分析:so that (it is almost impossible to tell whether girls are worse at science and maths) 表示因果关系的从句
be impossible to tell( whether girls are worse at science and maths )状语从句
这个句子的成分比较复杂
the difficulty is that by the time (when) children reach school age.这里when与by the time 是同一个意思
稍微理解了一些了吗