The difficulty of a problem was defined in terms of how long it took to complete.

问题的难易度是以解决这个问题所花时间的长短而定的。

《牛津词典》

It was up to him to make it right, no matter how long it took.

不管需要花多长时间，把事情摆平是他的责任。

《柯林斯英汉双解大词典》

Michael was ready: he wanted to see how long it took him to do a billion miles.

迈克尔已经准备好了：他想看看自己飞10亿英里需要多长时间。

youdao

He wondered how long it took a bird to die.

VOA: special.2010.03.20

But notice how long it took us to get there, how many centuries it took.

但是要注意到这要多长时间，它花了多少个世纪。

耶鲁公开课 - 新约课程节选

"Insurgencies last a long time." "But,as you look at how long it took to turn Iraq around, it was about 18 months.

VOA: standard.2010.07.22

That, in turn, made it possible to determine how long it took each group to reach a consensus, defined as concentrating more than 90% of activity around a single patch.

ECONOMIST: Human communication: Gesture politics | The

The McCain camp would not reveal precisely when the vetting process took place, how long it took or who else was vetted. iReport.com: What do you think of Sarah Palin?

CNN: After revelations, McCain gives assurances on Palin vetting

It has often been noted how long it took for the Burgess, Maclean, and Philby cases to dislodge the assumption that a certain class of person was more likely to be loyal to his country than the rest.

NEWYORKER: Hand on the Shoulder