Answer:
The Birds flew south to their winter home.
Explanation:
When you study basic English Grammar one of the first topics is the personal pronouns:
I ( Singular)
You ( Singular or plural)
He ( Singular)
She ( Singular)
It ( Singular)
We (Plural)
They (Plural)
The Pronoun The birds must be substituted by They flew south.....
Answer: One must mourn before moving on
