试想，30年前有人发明了能让我们与世界上任何一位朋友交谈的咒语 — — 只消念一句“约翰来 ” ， 你就能和约翰聊天了。
Imagine that 30 years ago, someone had discovered a set of magic words enabling us to speak to any friend anywhere in the world – “abracadabra John” and you were talking to John, wherever he was.