EARLY in the morning on Tomb Sweeping Day (清明节), 17-year-old Li Yang and his classmates walked through the rubble (废墟) of Beichuan Middle School to mourn his fellow students and teachers who died during the May 12 earthquake. They came in groups of three or four, and brought candles, incense (熏香), flowers and even letters to mourn the deceased (已故的).