"This is ground zero for the nation." Democrats in the state Senate fled to the neighboring Midwestern state of Illinois.

VOA: special.2011.02.25

Well, the energy at infinity is zero -K and the energy in the ground state is minus K.

无限远处的能量值为,而基态能量值为。

麻省理工公开课 - 固态化学导论课程节选

Looking down 10 stories over Ground Zero, Marine Corporal Jonathan Rist said he hoped the new construction going on below would not remove every last shred of the buildings destroyed in the terrorist attacks of September 11,2001.

VOA: standard.2009.08.01

In the vote Tuesday, New York's Landmarks Preservation Commission denied landmark status to the 19th century building that now occupies the site of the proposed 13-story, Commissioners ruled that the building, which is not within view of ground zero, lacks distinctive architectural or historic value.

VOA: standard.2010.08.03