People wearing masks stand at a bus stop in Zhengzhou, Central China's Henan province, July 13, 2011. Tens of people organized the event to raise the public awareness of orderly queuing at bus stops in the city that is known for overcrowded buses. The Chinese characters on the T-shirt read "Stop squeezing." [Photo/CFP] 

People wearing masks stand at a bus stop in Zhengzhou, Central China's Henan province, July 13, 2011. [Photo/CFP]