A Washington landmark, Dupont Circle, became ground zero for a massive, friendly snowball fight that was organized on Twitter and other social networking sites.

VOA: standard.2010.02.07

So, actually I want you to go ahead in your notes and circle that zero point and write "not a node."

在你们笔记上把这个零点圈出来,在旁边写上“不是节点“,它不是节点“

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