This will happen within two hours of breathing in this amount of carbon monoxide.

VOA: special.2010.02.02

The older kind of submarine used in World War Two could stay under water for only about forty-eight hours.

VOA: special.2010.06.11

It will result in head pain, stomach problems and a feeling of tiredness after two to three hours.

VOA: special.2010.02.02

They even found a measurable increase in the condition for every two hours sitting in a car.

VOA: special.2009.07.14

The studies found that the mistake rate in two intensive-care areas decreased when interns worked fewer hours.

VOA: special.2010.07.13

The material and the bacteria were kept warm in an incubator for two hours.

VOA: special.2010.12.07

In two thousand three, the Council reduced the hours that residents may work.

VOA: special.2009.06.02

It traveled two thousand one hundred kilometers in less than ninety hours.

VOA: special.2010.06.11

The two sides struggled for hours in the hot summer sun.

VOA: special.2009.09.24

She says being a mom is hard. "Because you have to get up every two hours in the middle of the night, and you can't go out and say 'I am going to buy this for myself.'

VOA: special.2010.05.13

Dr.Brook says just one to two hours of breathing automobile exhaust in traffic can be deadly.

VOA: standard.2010.08.04

In the hours that followed,two bombs, also targeting police, exploded in the capital.

VOA: standard.2010.05.10

"The unanticipated consequence is that people are now crossing less frequently and have to wait one to two hours coming in and out of our ports of entry."

VOA: standard.2010.04.21

It was a different era. But General Myers spent many hours in the White House Situation Room, working with Bush administration officials on strategy for the two conflicts, just as current top officers are working with President Barack Obama and his team now on how to move forward in Afghanistan.

VOA: standard.2009.10.16