In my opinion, you can use it to define words and find more suitable words (they usually have a thesaurus built into the definition), and find words that seem more elegant or mature.
Answer:
B
Explanation:
The passage isn't written hurried, uneven, or intense. it's a smooth and mellow pace very steady and measured
C. The main idea is the primary point of a piece of writing :)
The answer would be C.
Hope this helps:)