About three hours north of Port-au-Prince, the Artibonite Valley is the center of Haiti's rice production.

VOA: standard.2010.04.29

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

President Obama and 18 members of his national security team spent about three hours in the White House Situation Room Wednesday, assessing their Afghanistan policy.

VOA: standard.2009.10.01

That is because out of three days and two nights, the families will only see each other for a total of about 11 hours.

VOA: standard.2009.09.26

"Now we have what we would call rush hour conditions or peak travel conditions for as much as eight hours during the day - about three to four hours in the morning and similar time in the evening."

VOA: standard.2010.07.26