marshmallow , the second White House Science Fair in Washington.棉花糖， 第二屆在華盛頓白宮科學展。

(Reuters)
February 7, 2012 « Day in Photos http://blogs.voanews.com/photos/2012/02/07/february-7-2012/

AFP PHOTO / Saul LOEB
Photo: SAUL LOEB, AFP/Getty Images / 2012 AFP
President Obama tours White House Science Fair - seattlepi.com http://www.seattlepi.com/national/article/President-Obama-tours-White-House-Science-Fair-3114953.php