Hello. Will you please help me with the following:

Question

1)Which article is to be used in "This event caused a/the exodus of British citizens."
2)Is "get acquainted with" possible with inanimate nouns (facts, situation, idea, concept)?
3)Is it possible to say "for a lot of years" or is it "many"?
4)Is "argument" a synonym to "dispute" and do they need articles (It has become the subject of (an?) argument; It is the reason for (the?) argument.
Thank you for your time and help.

Answer 1

1) the

2) Yes.

3) Both are correct.

4) Yes. They need articles.