如果是表示時(shí)間段的詞組作動(dòng)詞賓語(yǔ)可以是用how long 來(lái)問(wèn).
I spent three days on the work.
It took me three days to do the work.
I need three days to finish the work.
對(duì)three days 提問(wèn)都用 How long
如果是表示時(shí)間的詞作介詞的賓語(yǔ)就具體問(wèn)題具體分析了.但是你所說(shuō)的介詞后的表示時(shí)間的賓語(yǔ),一般就說(shuō)是時(shí)間狀語(yǔ),不再分作介詞和介詞賓語(yǔ)了.不及物動(dòng)詞后面加了介詞在加賓語(yǔ),一般叫做介詞賓語(yǔ)了吧.lookat the blackboard中的the blackboard 是介詞賓語(yǔ).