Olive Oil
You probably have never given it a second thought, but storing olive oil in the refrigerator is not something you would want to do, unless you want some butter. The cold in the refrigerator will only turn the olive oil hard and condensed. You should instead store it somewhere dark and cool.
Onions
Just like garlic, when you leave onions inside the refrigerator, they will only become moldy! If there are some unpeeled onions lying around in your house, be sure to leave them in an area that is dark and dry because they need air ( but not cold fridge air) to stay fresh for a long period of time. If you have an onion that has been peeled, then place in a covered container and keep it inside the refrigerator.