Mister Weindruch says researchers do not know why reducing calories increases the length of life.

VOA: special.2009.09.01

They do not know why all these things were found together in one place.

VOA: special.2010.08.03

Scientists do not know why women are more at risk than men.

VOA: special.2009.04.14

Researchers do not know why happiness increases as people get older.

VOA: special.2010.08.03

Doctors do not yet know why this is true.

VOA: special.2010.06.15

"We have had a lot of inquiries about that,". "And it does not have anything to do with why we are actually down there.

VOA: standard.2009.10.20

"I saw all these ships waiting out there,I am guessing, waiting their turns to load and unload the cargo, so,I said,Why do the ships come into the harbor?" Why not have the harbor go out there and bring the goods in?'" Researchers describe the mobile harbor as a lean, light system for unloading container ships even if the coastal area is too shallow for them to dock.

VOA: standard.2010.01.04