Does multitasking on the iPhone drain battery life?

I've been hearing rumors that if you use the Facebook app for example, and you click out of it, iOS will stop the app from running yet still keep it open, thus it would not drain battery life while your not using it.

But is this true? When you have multiple apps running at the same time do they really drain more battery?

My iphone 4s got wet and won't turn on what should i do?

Sorry for my bad spelling. My company is sprint. I have an iphone 4s and i bought it off evay so no warranty. I was at the river and my brother tried to take a picture with my phone. He went into the water and was almost drowning then i grabbed him and took him to shore. I then took a look at my brother he was ok but my phone a little wet. It turned on but had some dirt in the recharge hole. None in the earphones plug since my earphones were in it but it looked fine. The botton was stick and hard to use and whenever i shut it off it would trun itself back on. Now its not responding at all and not even while i tried to recharge it. I had notes, pictures and contacts and i'm not sure if icloud got it all is there a way to fix my iphone 4s or at least salvage my memory?

What parts will I need to fix my iPhone 4?

I'm not sure what parts I will need to repair my iPhone 4 for verizon. So my friends gave me the phone after he through it at his windshield. So there's a server crack in the front. I tried to turn it on but the LCD screen will not turn on. Only a small light leaks though the broken part where you can see the internal parts of the phone. I would imagine I need the screen and LCD part too but just making sure before I waste my money.

Will apple replace my iPhone even though its customized?

So I got an iPhone off of eBay a few month ago and of course it has some problems like the home button not working properly, the speakers don't work, the promoxity sensor doesn't function, etc. And it wasn't abused or neglected or anything like that.
I'm not under warranty so I'm aware of the 149 dollar fee to replace it. But will they let me do that still even though there's a customized pink backing on it?

MacBook Pro vs iPhone 5 camera?

Which camera is better as far as quality? I want to start making YouTube videos with the two cameras that I have now on my iPhone 5 and MacBook Pro and I would like to make my videos as HD as possible.

How to make the ipod 4th gen look like an iphone?

What apps can i get? Texting apps, siri apps stuff like that, some cases or whatever, also what kind of things can i do to get internet anywhere? Any free internet stuff or cheap ones? Please don't call me a poser or anything rude i will block and report you, thanks!

Is it possible i can burst my eardrums?

I listen to music everyday for about 4 hours. I have these earbuds and i hook them up to my iphone, i keep them as loud as three of those notches, like on iphone or ipod when you turn the volume up or down and there's those little squares that tell you how loud it is, i keep it to a maximum of three of those little squares, i try not to get them louder than that… Can i burst my eardrums this way?