丹崖青嶂，它是石头;壁立千仞，它是石头;即使重峦叠嶂，耸如云天，它仍是石头。
B-Thing I-Thing I-Thing I-Thing O B-Thing O B-Thing I-Thing O O O O O O B-Thing O B-Thing I-Thing O O O B-Thing I-Thing I-Thing O O O O B-Thing I-Thing O B-Thing O O B-Thing I-Thing O