I understand that you're working on the Biology 106 human microbiome project and I'd be glad to help. What I would recommend is that you start by doing a few separate searches using the Articles search tab on the library homepage at http://cwi.edu/library.
Your assignment requires you to choose two topics to compare across two nations, right? So the best approach to this is to do a piece-by-piece search. If your two countries are the US and Norway and your two topics are, say diet and hygiene, search each of those pieces one at a time, like this:
- Search for articles on US and diets
- Search for articles on Norway and diets
- Compare the two
- Search for articles on US and hygiene
- Search for articles on Norway and hygiene
- Compare the two
Does that make sense? If you try this and still don't feel like you're finding what you need, let us know and we'll be glad to help you in more detail.