Answer:
Dialogue can help you establish the backstory, and it can reveal important plot details that the reader may not know about yet. Dialogue is great for ratcheting up the tension between characters. Dialogue can also establish the mood.
Explanation:
Hope this helps!
In Act 1
Ragueneau and Le Bret discuss Cyrano's nose. They are joking if the nose is real or not, and Le Bret responds "He keeps it on, - and cleaves in two any man who dares remark on it!"
"He keeps it on" simply means it really is his nose
and "cleaves in two" he will fight anyone who makes fun or "dares remark on it."
I’m pretty sure it’s the second obe