Question

we tried to steady ourselves with our walking sticks but slipped and stumbled because of the jumbled rocks we were slipping on. 3 every thousand feet, we came to a small station constructed of tin and cement, barely able to block the wind. at each one, we noted the roof piled high on fallen rocks and felt both unsettled and reassured by this evidence of the station’s protective ability. we rested uneasily for a moment as a clerk burned the station brand into our walking sticks which it was proof of our progress through the darkness. 4 as we neared the summit, the whole group of hikers—thinly spread across the mountain for most of 18. f. no change g. even though we used our walking sticks. h. despite any efforts to remain steady. j. with each step. 19. a. no change b. piling high with c. piled high with d. piling high on 20. f. no change g. sticks, it was proof of h. sticks, proof of j. sticks proved 21. a. no change b. the most part c. majority

Explanation:

1. For question 18: The original phrase is redundant ("slipped and stumbled because of... we were slipping on"). Option G clarifies the contrast between using walking sticks and slipping without redundancy.
2. For question 19: "Piled high with" is the correct collocation to describe rocks accumulated on the roof, replacing the incorrect "piled high on".
3. For question 20: Option H uses an appositive phrase to concisely explain the purpose of the brand on the sticks, fixing the run-on sentence in the original.
4. For question 21: "For the most part" is the standard idiomatic phrase that correctly replaces the awkward "for most of" to describe the hikers' spread.

Answer:

1. G. even though we used our walking sticks.
2. C. piled high with
3. H. sticks, proof of
4. B. the most part