課本中不會教你的[I]369　in doing和on doing

369　in doing和on doing

① in doing意為“在做某事時”，in相當于 when 或 while。

In walking past the library，I met Professor Wang.我路過圖書館時，碰見了王教授。（=When I was walking…）

In reading a collection of poems in my study，I heard a bird twittering outside the window. 我在書房里讀一本詩集時，聽到窗外有一只鳥在叫。（=While I was reading…）

② on doing意為“一……就”，on相當于 as soon as，immediately。

On arriving there，we all set to enthusiastically. 我們一到那里馬上就干勁十足地干了起來。（=As soon as we arrived there…）

On hearing “help”，he rushed out. 他一聽到呼救聲就沖了出去。

提示

on doing 也可表示“在……的時候”。

On turning the corner，she saw a skyscraper. 拐過街角，她看見了一幢摩天大樓。