When you read GRE passages, dont let the details bog you down. Most of the questions will ask about the structure of the passage rather than specific facts. If you need the facts, theyre always there in the passage. Theres no need to worry about what you know or dont know about the topic. The information is based on the information in the passage.
Most details are irrelevant.
The first sentence of the paragraph is often the topic sentence. View key sentences by scrolling through the passage. Do a mental wrap-up. Before moving to the questions, pause for a few seconds and review what you have just read. If a problem-solving math question stumps you, work backwards from the answers and eliminate choices that are completely off the radar screen.