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Hey @cassieguo1987
You could – there is some changes and they’re all listed here: hey mebhatia – you can get a good idea of what’s changing using this: http://www.elansguides.com/docs/Los-changes-2013-2014.pdf
However I’d recommend getting the latest – it’s just easier and you want to be focusing on studying rather than worrying whether you’ve missed a particular topic because it’s new, or overstudying on topics that aren’t relevant anymore.