The researchers say more studies are needed to learn the reason for the different effects of tobacco smoke on boys and girls.

VOA: special.2009.01.13

They are the reason for the many different kinds of life on Earth.

VOA: special.2009.12.01

But eighteen-year-old Julia Holmblad joined the group for a different reason.

VOA: special.2011.04.01

"I think we have to explain why this alliance that was started 60 years ago for a totally different reason is something that's important now.

VOA: standard.2010.06.11