Take a deep breath and see how long you can stay underwater.

深吸一口气，看你能在水里待多久。

《牛津词典》

Please tell me how long you have learnt English.

请告诉我你学英语多久了。

youdao

Could you tell me how long you have stayed here?

能告诉我你在这里待了多久吗？

youdao

You might have to stay away from low-lying areas for as long as twenty hours after the first warning.

VOA: special.2011.06.07

- So in fact, if you want a super long number -- -- let me go ahead and reopen this program -- long you could declare long.

所以事实上，如果你需要一个超级长的数字-,让我们继续重新讨论这个问题-,你可以声明。

哈佛公开课 - 计算机科学课程节选

you could maybe be speaking with a friend who talks about his long work hours and you are very surprised,

在你跟一个朋友聊天时，他谈起自己很长的工作时间，而你感到非常惊讶，

Do you ever课堂 - SpeakingMax英语口语达人

Decide how long you can struggle before one or both of you has to walk away.

FORBES: Look Before You Leap into a Partnership

Ask your doctor how long you will need to continue taking these medications once you recover.

CNN: Broken heart syndrome

You may start by asking yourself how long you think you might live. 30-50 years?

FORBES: Why the Buy and Hold Strategy Can Work. Part Three