You can, if you purchase an unlocked one, or unlock a locked one via codes. You will have to perform the USA Band unlock, starting with 2.4.x firmware, and upgrade will only be available via a special method described on RootzWiki.
You won't be able to use 3G. At all. A956 does not support the 1700MHz band.
You need Real-World Battery Saving Tips for your Android device. Our … more
20 Sep 2014
By Jimmy McGee
XDA Developers was founded by developers, for developers. It is now a valuable resource for people who want to make the most of their mobile devices, from customizing the look and feel to adding new functionality. Are you a developer?