Viruses change,or mutate, so flu vaccines must be reformulated each year to target the most common threats.

VOA: special.2009.03.04

One of the most common complaints he heard in developing countries was the lack of toilets.

VOA: special.2010.03.15

The most common seasonal flu virus found in the United States this year is type A(H1N1).

VOA: special.2009.03.04

They may struggle to hide them. Probably the most common early sign is short-term memory loss.

VOA: special.2011.02.08

Cleft palate and cleft lip are two of the most common birth defects in human beings.

VOA: special.2009.12.22

The most common problems were high blood pressure or other conditions linked to heart disease.

VOA: special.2009.06.09

But the most common cause is long-term smoking or years of breathing other people's smoke.

VOA: special.2010.06.23

Among the most common acts are fishing without permission and catching more than the limit.

VOA: special.2009.02.10

The most common answer historians give is that the name came from Samuel Wilson.

VOA: special.2009.09.25

He says one of the most common methods for suppressing weeds is dense planting.

VOA: special.2009.05.26

This is the most common cause of an unusual,or abnormal, heartbeat in older adults.

VOA: special.2009.09.22

The most common injuries were broken bones and sprains in legs and feet.

VOA: special.2009.12.09

The most common are infections of the urinary tract, surgical site and bloodstream.

VOA: special.2010.05.25

The most common form of arthritis, osteoarthritis,is more likely to affect older people.

VOA: special.2010.05.19