To get the most from your exercise plan, experts say adults should get at least two and a half hours of aerobic exercise each week.

VOA: special.2010.06.08

And if you are prepared to stand up for about two and a half to three hours to watch a play,

而且你要准备好了站上大约两个半小时到三个小时，去看一场戏剧，

莎士比亚环球剧院 - SpeakingMax英语口语达人

So I could do that in probably two and a half hours.

我可以用大约两个半小时的时间走完这段路程。

旧金山的公共交通 - SpeakingMax英语口语达人

He read for more than two and a half hours.

VOA: special.2009.05.14