It has set us back in so many respects that I'm not sure how long it will take for us to catch up.

我们在很多方面都被延误了，不知道需要多久才能赶上。

《柯林斯英汉双解大词典》

Part of it was just for fun, so I'd play around with maps and timelines I drew, so I'm not sure exactly how long I actually worked on it.

这有一部分纯粹是为了好玩，我会以自己绘制的地图和时间线为乐，所以我很难说我实际上是从什么时候开始真正致力于此的。

youdao

Do you think so? I'm not so sure. Anyway, tell me your plans for an Australian holiday. How long do you think we should spend there?

是吗？我不太清楚。无论如何。告诉我你的澳洲计划吧。你觉得我们得在那儿待多久？

youdao

In addition, if you are not sure how long your stay will be, Lonely Planet advises asking for the maximum amount of time: three months.

BBC: Search the