at a tangent的用法和樣例：
例句
- It's not easy to follow her think because she's always go off at a tangent.
要跟上她的思路并非易事，因為她老是突然扯到題外去。 - The teacher was telling us about the poet's life, when he went off at a tangent and started talking about his war experiences.
老師在給我們講述詩(shī)人生平故事的時(shí)候，突然把話(huà)題一轉，講開(kāi)他自己的戰爭經(jīng)歷來(lái)了。
