Premier Li Keqiang (left) gives a Luban Lock as a gift to German Chancellor Angela Merkel at the China-Germany Economic and Technological Forum during his visit to Berlin on Oct 10, 2014. Li said he hopes cooperation between China and Germany can keep evolving and improving. He said the two countries can cooperate to solve global challenges together just like unlocking the Luban Lock is a process of solving difficulties. [Photo/Xinhua]