Can you put a Verizon SIM card into a AT&T IPhone?

I have a AT&T Iphone 4s but there's no SIM card, I'm trying to sell it at gamestop but they need a SIM card in it for temporary use, just to get into the phone and make sure there's no software problems. Both phones are shut off, so it wouldn't be relying on the network just Wi-Fi, would it be able to work?

Fun, free, addictive apps on iPhone?

I'm looking for some fun and entertaining apps in the iTunes App Store. Not really a game, but maybe something more interesting. Are there any popular apps where you can interact with other people?

Why is my iPhone 5s acting weird? - 1

Whenever I have my headphones plugged in and listening to music or watching a video or if it's just plugged in music starts to fast forward, pause, skip, and voice control starts to come on and play music from different apps. Any help?

Will apple fix my jailbroken iphone?

I had a few months ago water damaged my iphone 4s and i'm afraid that apple won't support me if they found out i jailbroken the iphone,

I only use for a couple of Video game emulators and customization.
when apple sees my phone boot up they will see Mario jumping up and hitting a? Block with an apple logo coming out.So will they or will they not?