What happens next?

How to convince parents to let you get a gerbil
Get on the internet or go to your library and research all about gerbils :
Feeding habits, bathroom habits, how much you'll need to do to take care of them, etc. Gerbils are among the longest-lived and cleanest of common rodent pets. Also, get some really cute pictures of gerbils.

--Find out where you can get a gerbil and all the things it will need. Learn how much everything will cost and include that in your presentation.
--You can draw them, photograph them, or even just hang them on the wall of your pantry. Finally, offer to set the table for the gerbil.
--You don't have to buy one, but you can browse around to get a few of them. Using a pen and paper, write down a few things you might like.
--Ask your parents if they plan to buy or sell you any if it's likely you'll have to keep them. Most likely it will be expensive for you to purchase or to care for them.
Find out where you can get a gerbil and all the things it will need. Learn how much everything will cost and include that in your presentation.