Gradually, a chorus of grunts, thuds, snorts and belches can be heard from all directions.

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Week after week, on Louis Rukeyser's TV show, one guru belches 8100 while another burps back 14, 200.

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The next biggest source was enteric fermentation, scientific jargon for belches from cows and other animals, at 137 million metric tons.

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Jeff Portnoy (Jack Black), king of the gross-out comedies, who wants to show he's more than the sum of his belches.

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