A new exhibition by Chinese artist and architect Ai Weiwei opened at the Haus der Kunst yesterday. One of the exhibits, shown in part in the image here, covers the entire front of the building.It is made up of thousands of small backpacks, identical othere than in colour. The backpacks are the same as those used by Chinese schoolchildren and they are arranged to spell out the phrase 'she lived seven happy years in this world.' These words were spoken to the artist by the mother of Yang Xiaowan, one of the children killed in the Sichuan earthquake in 2008.