fly off on a tangent的用法和樣例：
例句
(ph.)
- We were discussing last night's concert when Anna went off at a tangent and started talking about her new flat.
當我們正討論昨晚的音樂會時，安娜突然離開話題，開始談起她的新公寓來了。 - It is difficult to have a sensible discussion with my mother because she's always flying off at a tangent and talking about something else.
同我母親進行有成效的討論很困難，因為她總是突然離開話題，扯到其它一些事情上去。
