The CBO projection is $7 trillion. The difference between the two estimates lies primarily in the fact that the CBO assumes the expiration of Bush administration-era tax cuts, while the White House is assuming that President Barack Obama will honor his pledge against allowing taxes to rise on families earning less than $250,000 a year.

VOA: standard.2009.08.25

And the answer lies clearly in the energy difference.

从能级差看，答案很明显。

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