案情:丁某与程某是邻居,两家素日礼尚往来,关系很好。1998年12月,程某请丁某义务帮忙伐倒院子里的一棵大杨树,同时还请了其他4名帮工。在伐树时,考虑到丁某己近年50岁,程某特别安排他在树桩处刨土。在程某到另一邻居家借绳子期间,丁某为替换另一帮工,持刀锯爬上树,在锯断一根大树枝后,因躲避不及,丁某被树枝打在脸上,并从10多米高的树上 Case: Dingmou and Cheng are neighbors, the two always beings reciprocity, good relations. In December 1998, Cheng Moumou Dingmou volunteer to help down a large yard in the poplar, but also invited the other four helpers. In cutting trees, taking into account Ding Mouji 50 years old in recent years, Cheng special arrangements for him to dig in the stump soil. Chengmou to another neighbor borrowed a rope period, Dingmou to replace another helper, knife saw climbed the tree, after sawing a large branch, due to escape too late, Ding was beaten on the face and More than 10 meters high from the tree