Hi Beat720,
There's no way to know what the exact subjects of your RC passages are going to be on Test Day, so you have to learn methods for RC that you can use to deal with ANY subject.
Since you're asking about RC specifically, I'm going to assume that you've done some studying already, so I have a few questions and then I can offer some suggestions:
1) How long have you been studying?
2) What practice materials have you been using?
3) How have you scored on your practice CATs (or on the Official GMAT)?
4) When are you planning to take the Official GMAT?
5) What is your score goal?
GMAT assassins aren't born, they're made,
Rich