It's not easy to follow her think because she's always go off at a tangent. 要跟上她的思路並非易事,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人生平故事的時候,突然把話題一轉,講開他自己的戰爭經歷來了。