Staffers do a final check on an unmanned plane to be used for opium reconnaissance, in Pinggu district of Beijing, on June 3, 2010. With the 23rd International Day against Drug Abuse and Illicit Trafficking approaching, on June 26, Beijing's first unmanned surveillance plane is being put into use along with a helicopter, as part of a month-long aerial survey program aimed at tracking down opium plantations and making sure the city's suburban areas are free of opium cultivation.[Photo/CFP]