San Diego Metro (Gallery) Pandas [1p.7n]Pandas:Washington D.C. [1p.1n]Pandas:San Diego [1p.1n] p1   p1   p1   Four-month-old giant panda cub Zhen Zhen plays with a ball in her enclosure at the San Diego Zoo during a media preview Friday, Dec. 21, 2007 in San Diego. Zhen Zhen and her mother Bai Yun will make their public debut at the Giant Panda Research Station exhibit on Saturday Dec. 22 click to open   p1   p1   p1