الماس طحن غطاء نقل الركاب والحمولات 10 مم
Free zones: Benefits and costs - OECD Observer. OECD Observer: Sections » Development . Since antiquity, governments, emperors, kings and queens have been providing traders and investors with special sites offering respite from normal import-export tax regimes and regulations in return for a steady stream of much needed revenue for the public purse.