Can you taste the difference between different brands of lemon-lime soda?

I would pick three differnt brands of lemon-lime flavored soda, Sprite, Sierra Mist, and 7-Up, and test about 20 people at least and test if they can taste the difference in the three brands. I would do this by blind folding them and giving them one of the sodas and asking them which brand they thought they were drinking. This is the topic I have decided to do.

What paper towel brand is the most absorbent?

I would choose three different paper towel brands. Next, I would pick the one that I thought was the most absorbent and my hypothesis would be that that brand would absorb the most water. I would then pour the same amount of water on one sheet of each brand. Whichever sheet had the least amount of water left on the table would be the most absorbent. This is my second option I would maybe like to do.

Does chewing gum help improve memory?

I would pick two people of the same age and give one gum but not the other. Then give them each a memory test and see if gum helps them remember things better. Then after the test I would see which person remembered more. My hypothesis would be that gum does help because it would seem like it would help you focus better, like during a test. I picked this expirement because I wanted to do something that involves memory and I really like gum, so I figured this would be perfect.  This is not one of my favorite choices.
http://www.juliantrubin.com/fairprojects/psychology/memory.html

Which fruit decomposes faster?

I would take an apple, an orange, and a pear and put them in my backyard and wait til they decompose. I would check them everyday and see how much they have.  My guess is that the orange will the fastest to decompose  because the inside if soft and mushy. I picked this experiment because we required to have one green option and this one seemed nice and simple. But, I am more interested in doing one of the others.