Chinese Vice President Li Yuanchao, the special representative of Chinese President Xi Jinping, delivers a speech during the memorial service for Nelson Mandela in Johannesburg, South Africa, on Dec. 10, 2013. Li Yuanchao on Tuesday expressed deep condolences and paid high tribute to former South African President Nelson Mandela, saying Chinese will always cherish Mandela's contribution to China-South Africa relations. [Photo/Xinhua]