Answer:
To improve document
Explanation:
Revising a summary might be beneficial if you want to search for errors you may have missed the first time. If you avoid grammatical and spelling errors, your document seems more professional. Also, another individual may provide additional words or phrases that are better than some in order to improve the appearance.
The answer is the fourth one.
I'm thinking either "Using numbers to help readers see the various steps easier," or "adding a supply list before the instructions." (I'm sorry I couldn't give a more clear answer, but I hope this helps narrow down the choices)
I think the answer is "each other" for all of them?