原告某甲在上班途中遗失金项链一条,价值3000余元。经查找,未有下落,遂于公众场合许诺:谁拾得后归还,愿重金酬谢。数日后,原告听说邻村某乙拾得金项链一条,便于次日到乙单位,请求乙单位领导做乙工作,拿出项链让其辨认,若确为自己所失之项链,收回后将以重金酬谢。乙表示,只要原告拿出2500元,就同意交出项链让其辨认。原告无奈之下,答应了乙的要求,将 A claimant lost a gold necklace on the way to work, worth 3000 yuan. After the search, there is no whereabouts, then promised in public places: who picked up after the return, willing to reward. A few days later, the plaintiff heard that a nearby village A pick up a gold necklace, easy to the next day to B units, B unit asked to do B work, took out the necklace to identify, if indeed lost their necklace, will be recovered Heavy reward. B said that as long as the plaintiff took 2500 yuan, agreed to hand over the necklace to identify it. The plaintiff desperation, agreed to the request of B, will