The Lehman Brothers bankruptcy on September fifteenth was a shock to the system, but not the only one.

VOA: special.2009.09.18

In the fifteenth century, a greenhorn was a young cow or ox whose horns had not yet developed.

VOA: special.2010.05.23

Then, on the night of February fifteenth, a powerful explosion shook the battleship Maine in Havana harbor.

VOA: special.2010.07.08

He was still working in Big Piney,Wyoming, when he died of a heart attack on January fifteenth.

VOA: special.2009.02.23

On April fifteenth he gave a speech in which he discussed his goals for space travel.

VOA: special.2010.04.28