I am a native English speaker and some of these are difficult. Here are my answers for my first try. I will come back to try more and put it in my comments. If it’s blank, I do not know the answer.
2.
3. machine
4.
5. Board
6. Paper
7. Card
8. Glasses
9.
10.
11. Coat
12.
13. Line
14. Horse
15.
16. Party
17. Name
18. Table
19.
20.
C - Beautiful antique instruments renames guitars
Appositives are nouns or noun phrases that renames another noun beside it. The phrase 'beautiful antique instruments' renames and is right beside 'guitars' as it is describing them.
A
I think this answer to be A. Clustering doesn’t make sense, if anything, it would make things more difficult. Keeping a journal wouldn’t exactly have any certain effect. A is the best option because authors often BRAINSTORM before writhing a paper