A、International experts. B、International organizations. C、American police. D、American experts. A

Experts from seven nations gathered at a Beijing conference Monday, contributing their ideas on security and counter-terrorism for the upcoming 2008 Olympics.
    International terrorism, highly-organized transnational crime and security issues for large-scale sports events are on the agenda for the conference, which is cosponsored by the Beijing Olympics security headquarters and the United Nations Interregional Crime and Justice Research Institute, said Ma Zhenchuan, director of the Beijing Municipal Public Security Bureau. Ma said Beijing has been updating police work and police methods, improving equipment and boosting the overall quality of police, in anticipation of the Olympic Games. He said Beijing police will actively cooperate and communicate with international experts and establish advanced security mechanisms.
    UN Deputy Secretary General David Veness said he appreciated China’s goal of a "safe Olympics". "We have seen tragedies occur at some sports events in recent years and do not want that to happen in Beijing," said Veness. He hoped that Beijing could draw some valuable lessons from the conference. "China has already cooperated extensively with our organization and we have witnessed the huge efforts made by China over the past few years," said the official.
    Beijing police have been testing security mechanisms since 2005 at many international sports events in the city, said Liu Shaowu, deputy director of the Beijing Municipal Public Security Bureau. Liu said the Beijing police will continue to work on Olympic security, and particularly risks represented by terrorism and organized crime.