You might have to stay away from low-lying areas for as long as twenty hours after the first warning.

VOA: special.2011.06.07

They were told to use the gels twelve hours before sexual intercourse and again within twelve hours after sex.

VOA: special.2010.07.21

The drug is nevirapine. If it is given within seventy-two hours after birth, it can often protect babies from H.I.V.

VOA: special.2010.05.24

A few hours after Brown was captured, the Governor of Virginia and three Congressmen arrived in Harpers Ferry.

VOA: special.2009.07.02

The plan seemed good. And after the first few hours of battle, the Confederates were close to victory.

VOA: special.2009.09.17

After thirty-six hours, Brown was captured in the building that served as the fire engine and guard house.

VOA: special.2009.11.06

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

VOA: special.2010.02.02

But experts generally advise against using the drug if more than three hours have passed after the first signs of a stroke.

VOA: special.2009.09.22

But traditional guidelines say not to use tPA if more than three hours have passed after the first signs of a stroke.

VOA: special.2009.08.12

Two hours after Apollo Thirteen went around the moon, the astronauts fired the rocket for five minutes.

VOA: special.2009.07.22

The chief justice of the United States swore Johnson into office a few hours after Lincoln's death.

VOA: special.2010.01.21

Vice President Arthur took the oath of office a few hours after the president's death.

VOA: special.2010.04.29

Faisal Shahzad was quickly identified and arrested fifty-three hours after the attempt in Times Square.

VOA: special.2010.05.08

Some studies have failed to produce clear evidence to support treatment after three hours.

VOA: special.2009.09.22

Two hours after he received the news, Tyler was on his way to Washington.

VOA: special.2009.01.29

Five hours after the explosion, flight controllers advised firing the rocket for thirty-five seconds.

VOA: special.2009.07.22

They came out four hours later after talks with the president and other officials.

VOA: special.2010.06.19

Also,doctors are advised to discontinue the antibiotics within twenty-four hours after the surgery.

VOA: special.2010.04.21

At last,after two hours, she sat down and ate like other people.

VOA: special.2009.11.08

Carbon monoxide levels in the blood return to normal after eight hours.

VOA: special.2010.03.09

Also,doctors are advised to discontinue antibiotics within twenty-four hours after the surgery.

VOA: special.2010.05.25

Three hours after leaving New Guinea, Amelia sent back a radio message.

VOA: special.2010.05.26

Two hours after arriving, they began to prepare the ground for planting.

VOA: special.2009.06.04

The president spoke just hours after North Korea launched a long-range rocket.

VOA: special.2009.04.11