howlong屬于什么知識點？

howlong知識點:

how long: 有多久，用來提問時間。

How long will the registered trade-mark remain valid ?注冊商標的有效期多長？

How long will this ability persist ?這種能力還能維持多久？

Well , how long have you studied english ?你學英語多久了？

How long does it take to get to tamsui by bus ?搭公共汽車到淡水需要多久時間？

How long can you hold your breath for ?你能屏住呼吸多久？

How long will you be staying in paris ?你在巴黎要呆多久？

How long will it take to set up the projector ?把這個放映機安放好需要多長時間？

How long has she been your favourite ?你看中她多久了？

How long are you staying in london ?你會在倫敦呆多久？

How long do you intend to stay ?你打算在這兒住多久？