The same “near field communication” chips enable phones to be used as train tickets and office passes, so acting as front-door keys or car keys as well would not be a giant leap.
2
在离开的前几天,我总算收到了预订的火车票,于是把信箱的钥匙还给了邮局。
I received the booked train ticket a few days before my departure, so I returned the key of the mail box to the Post Office.