Sometimes,observers see this as a comet's tail, which can be visible to the unaided eye stretching across the night sky.

VOA: special.2011.02.09

They include arsenic, which can be used to kill plants and small animals.

VOA: special.2010.03.09

It occurs as a result of something underlying which can be potentially serious."

VOA: special.2009.09.02

Most restaurants use large gas ovens and stoves which can be wasteful.

VOA: special.2009.04.10

It also causes bad side effects, some of which can be deadly.

VOA: special.2010.01.04

The games, which can be downloaded free, are designed to help young Americans explore careers in the Army.

VOA: standard.2010.04.20

Community leaders say donating basic goods like milk powder and aspirin, which can be scarce in Cuba, has a major impact for Cuban families struggling to survive under Communist rule.

VOA: standard.2009.10.23

"In recent years, the development of rapid, diagnostic tests for malaria, also known as RDTs, which can be performed by healthcare workers after a brief training has made the extension of diagnostic testing to rural health facilities possible."

VOA: standard.2010.03.09

The paper's authors tried to take into account other factors, but they admit it may not have been entirely possible to quantify differences in, for example,the recipient's health, which can be a big factor in the success of a transplant.

VOA: standard.2010.07.14

The first step uses a bit of influenza DNA to get the patient's immune system to begin fighting off the flu, and then the protection is given a "boost" some time later by the second step, which can be either another bit of DNA or a conventional flu vaccine.

VOA: standard.2010.07.21

Professor Gaechter says social order in general can be explained as a system in which individuals behave cooperatively and follow social rules.

VOA: special.2009.03.03

It can be given to children as young as one, which is earlier than vaccines currently used to fight meningitis epidemics in Africa.

VOA: special.2010.12.15

But the extent to which economic green shoots can be found depends on where you look.

VOA: special.2009.05.08

Then we come to a room in which dinner can be served to many guests.

VOA: special.2009.11.16