Hi, I'm quite interested in buying this phone, i just need a few details first. Can you use a sim card on the phone and if yes is it dual? Also, on one of the images viewing the nexus, you can quite visibly see a scratch on the back of the nexus, yet the description claims it to be new. The image also causes it to look like it is in a rough condition. Is this something i should be concerned about or is it just a distortion of the image, making things appear different?