Nitric acid + calcium carbonate
Hyudrochloric acid + magnesium carbonate
Sulphuric acid + magnesium

You have to do your homework yourself, of course !

Start with posting here in response the chemical formula for :

Nitric acid + calcium carbonate

Hydrochloric acid + magnesium carbonate

Sulphuric acid + magnesium

And I (and I hope also others) will help you from there.

Note : it is easy to tell you which gas you get.
But it is better to let you find that out yourself (that is if you want to pass this subject !)

:)