Level 3 articles are... tough. They are almost not adapted and are very close to real news articles. You´ll find there all range of complicated language constructions plus idioms, fixed phrases, and collocations. If you´re switching from Level 2, my advice is just to stick with it. At first, you´ll probably understand around 40-50% of the words, but remember that practice makes perfect. At this stage, there is no way back. You are that close to reaching an advanced level of Russian. And anyday that you open a Level 3 news and can easily read and understand it, that is when you know that you finally mastered Russian. High five!