this is ___the term it rains cats and dogs has come into usewhy how because because of
问题描述：
this is ___the term it rains cats and dogs has come into use
why
how
because
because of
答
选why.
译文：这就是为什么"倾盆大雨"这个术语已被使用的原因.
rain cats and dogs：下倾盆大雨
come into use：开始被使用