Nancy和舍友来到图书馆，本想进去参观一下，忽然被图书馆的管理员拦住，管理员对她们说"The school laid down the law, if you don't have a library card, there is no admittance"   Nancy心想这里的law应该不是指法律，是规章制度吧，为了以防万一，她问了问舍友，确认了一下。

    The school laid down the law学校立下了规矩。

    laid down the law  制定法律 这是最容易理解的字面意思 但是它在不同的情形下有不同的意思 比如在此处The school laid down the law学校立下了规矩

 下面给大家举个例子:

A：The teacher laid down the law today. Anyone who is late for his course will be punished to stand up ! So you'd better be careful.

      老师今天立下规矩，谁要是上课迟到就会被，所以你还是小心一点

B：Thank you for the advice.

        谢谢你的建议。