As poor as a church mouse
字面理解：像教堂里的老鼠一样贫穷
英文解释：very poor
中文意思：非常贫穷
例句：Nobody can imagine that Mr. Wang, the richest man in the city, was as poor as a church mouse when he was twenty.
没人会想到：本市最有钱的王先生在他20岁时，只是一个穷小子。
典故：中世纪的西方教堂里是没有放食物的柜子和储物室的，所以住在那里的老鼠总是挨饿。后来，老鼠就成了“贫穷”的象征
