千尺栋的石阶狭窄，只得用脚掌横踩着，而手用力拉紧从上方垂挂下来的铁链，逐级上行。
B-Location I-Location I-Location O B-Thing B-Location O O O O O O B-Thing I-Thing O O O O O O O O O O O B-Location I-Location O O O O O B-Thing I-Thing O O O O O O