https://online2.tingclass.net/lesson/shi0529/0009/9907/323.mp3
https://image.tingclass.net/statics/js/2012
讲解文本：
think on one's feet 急中生智，反应敏捷，随机应变
Mike is really good at thinking on his feet.
Mike很善于急中生智。
There's no time for getting ready.You have to think on your feet.
没时间准备了，你只能随机应变
疯狂练习吧!
