A leavening agent is an organism or substance that when added to a dough[?] of flour and water causes it to "rise" by evolving carbon dioxide or other gasses that become trapped as bubbles[?] within the dough.
... (1454-1512), discovered other parts of America and gave his name to the new continent
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Jean-Frédéric Waldeck, (1766-1875), French antiquarian, artist, explorer
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Si ...