Photos: Deep freeze strikes U.S.
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Hannah Wilcox, 5, pulls her younger sister, Sarah, 2, up the hill for another round of sledding just after 8 a.m. on Longwood Drive in the Hope Valley Farms neighborhood, in Durham, N.C. on Wednesday, Jan.29, 2013. School systems across much of North Carolina were closed on Wednesday. (AP Photo/The News & Observer,Al Drago)