他们在连绵起伏的崇山峻岭间艰难地跋涉，终于到达山顶天池，留下了一篇《封长白山记》。
B-Person I-Person O O O O O O B-Location I-Location I-Location I-Location I-Location O O O O O O O O O O B-Location I-Location I-Location I-Location O O O O O O B-Thing I-Thing I-Thing O O O O O