File photo taken on Aug. 23, 2014 shows people wait in line before the first birthday celebration of panda cub Bao Bao at the National Zoo, in Washington D.C., the United States. Named in honor of first American President George Washington, Washington D.C. or Washington District of Columbia is the capital of the United States that is located between Maryland and Virginia states. Overseas Chinese, Confucius institutes, giant pandas and Chinatown are characteristic Chinese features that can be find in Washington D.C. (Photo: Xinhua/Yin Bogu)
