这招总有一天会有用的，也是拥有一部手机的很好理由：如果你把钥匙锁在车里了而备用钥匙在家里，用你的手机往家里某个人的手机上打电话。

This may come in handy someday. Good reason to own a cell phone: If you lock your keys in the car and the spare keys are at home, call someone at home on their mobile phone from your cell phone.

youdao