You must measure the length by rule and line.

你必须准确地计量长度。

We must play the game by rule.

我们必须按照规则进行比赛。

Pay membership fees by rule.

按规定缴纳会费。

He has lived all his life by rule.

他已经按照准则生活了整整一生。

Do you talk by rule then, while you are dancing?

那么说，你跳起舞来照例总得要谈上几句吗？