A visitor enjoys art works at the exhibition "Raffael to Titian" at the Staedel Museum in Frankfurt, Germany, on Dec.23, 2014. The exhibition is held from Aug. 10, 2014 to Nov. 11, 2015, at which ninety works between the year of 1430 and the year of 1600 are presented. (Xinhua/Luo Huanhuan)
