向同学借尺子时，使用礼貌和委婉的语言是非常重要的。以下是一些更好的表达方式：

May I borrow your ruler？或 Can you lend me your ruler？

Hey! Can I use your ruler for a moment？

Excuse me, could I borrow your ruler？

I'm sorry to bother you, but could I use your ruler？

Do you have a moment？ I need to borrow your ruler.

这些表达方式都显得更加礼貌和委婉，能够减少对方的抵触情绪，增加借东西的成功率。希望这些建议对你有所帮助!