are more fragile than they appear. 其实要脆弱得多

250. mountains can be sanctuaries.
     深山堪称生存的圣殿
251. But rocky peaks which to us, perhaps,
     那些在我们看来
252. seem a symbol of permanence,
     似乎象征着永恒的岩石山峰
253. are more fragile than they appear.
     其实要脆弱得多
254. Today in the Alps,
     如今在阿尔卑斯山
255. human encroachment is changing even the highest summits.
     人类的侵犯甚至影响到顶峰的环境状况
256. In the Rockies,
     在落基山脉

来自《行星地球 第二季 第二集 Planet Earth S02E02 山脉》第 253 行