Grammer

[puzzle]

I." Who is he?"
"He is Tom."
II."Who was he?"
"He was Tom."

My question is: when should I use the second dialogue? It's the same with the first dialogue? Pls.

[puzzle]

I. " How about the job you mentioned?"
--" I get it!"
--" I got it!"

II. "What's wrong with you?"
--" I have a trouble."
--" I had a trouble."

III. "Hi,Jack!"
-- " Hi, what brings you here."
-- " Hi, what brought you here."

Iv. " I heard he was arrested."
-- " see, he deserves it ."
-- "see, he deserved it."

As you see there are two answers for each dialogue, could you tell me which one is right, or both are right? Pls.

[puzzle]

Any help?

[puzzle]

nobody can help me?