Question

一道初中英语例题，求答案解析

He was (so) foolish (that) he didn't pass such an easy exam.
为什么括号内用的是so而不用very?
that为什么不可以换成because？

Answer 1

so ...that是短语，如此以至于，so可以换成very,但是后面不能加because,因为because引导句子，换了以后这就是两个句子放在了一起。