Kaplan's Five Basic Principles of Test Expertise
It's imperative that you remain calm and composed while working through a section. You can't allow yourself to become so rattled by one hard reading passage that it throws off your performance on the rest of the section. Expect to find at least a few killer questions in every section, but remember: You won't be the only one to have trouble with them. The test is curved to take the tough material into account. Having trouble with a difficult question isn't going to ruin your score, but getting upset about it and letting it throw you off-track will. When you understand that part of the test maker's goal is to reward those who keep their composure, you'll recognize the importance of not panicking when you run into challenging material.