Yesterday I wrote about paraphrasing in the context of writing task 1. But paraphrasing is even more important in the reading test.
In every IELTS reading test, the majority of questions paraphrase something from the passage. If you can find and understand the part of the test that has been paraphrased for each question, you'll probably get the right answers. When I write about the "keyword technique" in my lessons, I'm really talking about paraphrasing.