How long does it take to qualify?

需要多长时间才能取得资格？

《牛津词典》

How long will it take her to swim the Channel?

她游过英吉利海峡得用多长时间？

《牛津词典》

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》

"No matter how long it may take us to overcome this premeditated invasion, the American people in their righteous might will win through to absolute victory...

VOA: special.2011.06.02

Said a different way, in the case of the straight-line programs, how long would it take to run a program?

换种说法，在直线式程序里面，运行一个程序要多长时间？

麻省理工公开课 - 计算机科学及编程导论课程节选

But I don't really know about how long it would take people to hack, like, the general firewall

但我不知道人们具体要用多长时间才能穿过防火墙，

理想是当密码专家 - SpeakingMax英语口语达人

And what is more, scores of African soldiers seem to be paying the ultimate price to contain this growing threat and it is difficult to gauge how long it will take to end it all.

BBC: African viewpoint: Pock-marked politics

"In StarCraft II, the leagues aren't established yet, they're all building up -- it's going to be huge, but we don't know how long it will take, how huge it will be, whether (existing teams) will be good at the game or not, " Fields said.

CNN: StarCraft II shakes up S. Korea's `national sport'

If I decide to take medications, how long will it take for my symptoms to improve?

CNN: Phobias