Fill in the context of climbing exam

Answer:

But when you walk up a flight of stairs (right on your back), you broaden your horizons by 300 miles.

I came from three thousand miles away. Sad now and autumn ("doing" is easily mistaken for "doing")

Sunset and lonely Qi Fei ("I" can easily be mistaken for "I")

It's better to be knowledgeable than to look at it ("help" is easy to write wrong)