Avoid exercising within three hours of bedtime.

就寝前三个小时之内不要有体育运动。

youdao

It is possible for him to finish the work within three hours.

要他在三小时内完成这项工作是可能的。

youdao

Crews put out much of the fire within three hours although smaller fires were still burning.

消防员3小时内控制了大部分火势，不过仍有零星火焰燃烧。

youdao

And now when I go into a lecture, the nervousness-- because I give myself the permission to be human-- goes away within as little as three hours into the lecture.

现在当我去上课时，紧张感-,因为我准许自己为人-,在课堂进行三小时后会消失。

哈佛公开课 - 幸福课课程节选

The police ombudsman for Northern Ireland reckons to have an investigator at the scene of a shooting within three hours.

ECONOMIST: Second-guessing the police is a hazardous business

New clot-busting drugs allow some stroke patients to make a full recovery if treated within three hours of their attack.

CNN: Bluetooth device to save stroke victims

In 2002 rt-PA was given an EU licence on condition it was used on patients under 80 within three hours of them having an ischaemic stroke.

BBC: Brain