The factories, which buy cheap crude and turn it into fuel, are struggling as higher oil prices threaten their razor-sharp margins The factories, which buy cheap crude and turn it into fuel, are struggling as higher oil prices threaten their razor-sharp margins T he towns that are the bulwark of China’s energy security can, at a moment of global crisis , appear deceptively quiet. Trucks carrying oil trundle along wide-open highways that have little traffic, while a few boarded-up shops in