Schools without a nurse on duty may be more likely to send an injured child to a hospital.

VOA: special.2009.08.06

So the Institute of Medicine proposed that residents be required to get five continuous hours of rest for every sixteen hours on duty.

VOA: special.2010.07.13

He was on duty when the passenger ship Titanic sank in the Atlantic Ocean in nineteen twelve.

VOA: special.2010.01.31

It will house 8,000 people in tents. Fifty security guards will be on duty around the clock.

VOA: standard.2010.03.29

According to the U.S.-based Committee to Project Journalists, at least 17 foreign and Afghan journalists on duty in Afghanistan have been killed since the 2001 invasion to oust the Taliban from power.

VOA: standard.2009.09.10

In another famous illustration, "The Army of the Potomac - A Sharp-Shooter on Picket Duty."

VOA: special.2010.07.25

Each day,thousands of Americans are called to serve on jury duty.

VOA: special.2009.08.31

The U.S.military uses dogs to help troops on sentry duty and bomb-sniffing patrols.

VOA: standard.2010.05.18

Speaking at the vigil, New York City Mayor Michael Bloomberg said it is the "sacred duty" of New Yorkers to carry on the memories of those lost.

VOA: standard.2009.09.11

U.S.Army Sergeant Jeremy Tormala, on his second tour of duty in Iraq, thought the elections gave a good indication that Iraqi forces will be up to the task.

VOA: standard.2010.03.08