More than 20 of the 50 American states ban smoking in public places.

VOA: special.2009.01.07

I've gotten pretty far in my life, and as far as I can tell I've never, ever, ever had to remember the capitals of the 50 states.

都这么多年了，我还记得我从来没有，需要住50个州的首府的时候。

耶鲁公开课 - 死亡课程节选

Many motor home owners have driven to all 50 U.S.states - except,of course,Hawaii, way out in the Pacific Ocean.

VOA: standard.2010.03.01

That large data set allowed them to analyze information for the 50 U.S.states separately, and also to identify trends by race and gender.

VOA: standard.2010.08.10

Nicaraguan President Daniel Ortega's 50-minute address included a long list of grievances against the United States.

VOA: standard.2009.04.17

Tens of thousands of Scouts from all 50 states and 26 other countries come to the United States every four years for 10 days of adventure and fun.

VOA: standard.2010.07.31

While 29 of the 50 U.S.states have laws that protect the rights of smokers, Weyco an insurance benefits administrator in Michigan, began imposing random smoking tests in 2005 on its own employees.

VOA: standard.2010.02.18