A farmer tends to his flock in a field shrouded in haze in the town of Lu Cheng, located around 80 kilometres (50 miles) northeast of Beijing July 4, 2008. Authorities in Tangshan, an industrial city in Hebei province north of Beijing, have ordered 267 firms to shut down operations by July 8 to improve air quality ahead of the Olympics, government and industry sources said on Friday. The firms include 66 steelmakers, as well as coke plants, cement firms and small power generators, a government official in Tangshan said. REUTERS/David Gray (CHINA) (BEIJING OLYMPICS 2008 PREVIEW)