ORLANDO, June 14, 2016 (Xinhua) -- Photo taken with mobile phone on June 13, 2016 shows a customer looking on an AR-15 semi-automatic rifle at a shop in Orlando, the United States. The American society has been buzzing with measures to prevent further gun-related violence in the United States, after a shooting spree in an Orlando nightclub left 49 dead and 53 wounded on Sunday. (Xinhua/Yin Bogu)