rabbit's foot其实是“幸运符”的意思。在很多英语国家佩戴“兔子的后脚”是一种习俗，据说每当需要好运的时候，只需要摩擦随身携带的兔子脚好运就会到来。

【例句】
If they ever took an exam who used to take a rabbit's foot into it?
如果他们参加过考试，习惯把幸运符带到考场上？

Carrying a rabbit's foot brings good luck.
提起兔脚可交好运。