It probably comes from an expression used for many years by people who fix parts of cars and trucks.

VOA: special.2009.11.29

It is cut to the chase. She heard that expression when she attended an important meeting of one company.

VOA: special.2010.07.25

Speaking of personal questions, there is an expression people sometimes use when their children ask, "where do babies come from?"

VOA: special.2009.06.28

Other experts say the word cheese in this expression was really an incorrect way of saying chief.

VOA: special.2011.05.08

So it is not surprising that top is part of another expression that describes an important person.

VOA: special.2009.11.29

Another common expression, to hold water, is about the strength or weakness of an idea,opinion or argument.

VOA: special.2009.05.10

An old expression of the sailors that is still heard is to sail under false colors.

VOA: special.2009.05.24

But an official of the American space agency,NASA, says the expression just grew.

VOA: special.2010.06.27

but to make their own. The primary or fundamental movements of the new school of the dance must have within them the seeds from which will evolve all other movements, each in turn to give birth to others in an unending sequence of still higher and greater expression,thoughts,and ideas.

VOA: special.2010.08.29

Clinton's comments at a joint press event with the Uruguayan leader were the highest-level expression of U.S.concern thus far about a Venezuelan arms buildup that gained momentum with an announcement this week that the South American state will buy Russian battle tanks and anti-aircraft missiles.

VOA: standard.2009.09.15