The tips begin at a different place in each module. The advice moves along with the stages of the course.
In MCAT passages, your knowledge base makes the details come clear in the light of fundamental principles. Reading an MCAT passage is like clearing a field. However, sometimes you might run up against a stump or a boulder, an out-of-scope reference, a purposely cryptic description, a table of contradictory data. Seeing how you handle this type of thing is intentional in the test design. You are not in trouble. Just fence that off. It is an indeterminacy. Develop a provisional understanding. Formulate an open question. How you handle what is purposely designed not to be clear is one of the challenges of the test.