translation.en: But what really matters is two kinds of problems -- problems that occur on the mountain which you couldn't anticipate, such as, for example, ice on a slope, but which you can get around, and problems which you couldn't anticipate and which you can't get around, like a sudden blizzard or an avalanche or a change in the weather.
translation.zh: 但是真正重要的是 两种问题-- 一种在上山时 你不能预料到的问题， 例如，坡上的冰， 但你可以绕过去， 还有一种问题是你没能预料到 并且你不可以绕过去的问题， 就像突然暴雪或雪崩 或天气突变。