https://online2.tingclass.net/lesson/shi0529/0009/9907/505.mp3
https://image.tingclass.net/statics/js/2012
讲解文本：
one and only 惟一的，仅有的，独一无二的
For several years they've been each other's one and only.
这几年来，他们都是彼此的唯一。
This is my one and only chance to do something.
这是我唯一的机会。
疯狂练习吧!
