China declared Thursday it was ready to stage one of the greatest Olympics ever, even as pollution concerns and human rights controversies hung over final preparations for the opening ceremony on Friday (3 P.M. KSA time) As the world's best athletes poured into Beijing and the Olympic flame passed over the Great Wall, Games organizers sought to shift global attention to what they promised would be a spectacular celebration of sport. “We have prepared for the Beijing Olympics for seven years and now we are ready... we are very confident indeed that we will stage a successful Olympics,” organizing committee spokesman Sun Weide said. “Of course we hope that these will be a great Games, even the greatest.” For China, the Games are an opportunity to show the world how far it has come since the communists came to power in 1949 following a brutal civil war, and particularly the past three decades of phenomenal economic development. The Olympics offer to highlight China's social and economic transformation, similar to the 1964 Games for Japan and the 1988 event for South Korea. “China is a nation in transition, with a great future, tremendous potential and some challenges,” International Olympic Committee president Jacques Rogge said after arriving in Beijing. “I believe history will view the 2008 Olympics as a significant milestone in China's remarkable transformation.” Nevertheless, the vast array of controversies that have swirled around the Olympics this year continued to bedevil the Chinese leadership, from the smog that has stubbornly hung over Beijing to human rights storms. A mixture of pollution and fog again cut visibility across Beijing despite much publicised emergency measures to improve air quality. The pollution has been particularly embarrassing for China because it has highlighted to the world one of the worst side-effects of its historic modernization drive -- massive environmental degradation. Enthusiasm for the Games among China's more than 1.3 billion people has been so strong that tickets have sold out for the first time in Olympic history. More than 100,000 security personnel are patrolling Beijing, anti-missile barriers have been set up near the “Bird's Nest” Olympic stadium, and the military and police are on guard around the country.