20.
Your Answer is
Correct Answer is H
Explanation
H item proof is an apposition of station brand. Burn a station brand into our walking sticks refers to "printing the name of the station on our walking sticks as a sign of our progress".
F item: which guides the attributive clause to act as the subject or object in the clause, F item does not lack the subject or object, wrong.
Item G: Commas cannot be used between two complete sentences.
Item J: The error is a complete sentence before the sticks, and a verb proved cannot be added.