Students spend hours doing exercises from workbooks but forget that to learn a language, you have to commit things to long-term memory and in my experience that involves looking at things between 10 times( if you are a genius) and 30+ times ( if you are a very experienced student). In the Advanced exam you have 4 readings and 4 grammar/vocabulary parts to do in 1 hour 30 minutes, which is far more demanding than the First Certificate (B2) and Proficiency (C2)exams, where you are only given 3 readings to do. If you have been teaching them the technique for one of the Use of English exam questions, then do another timed practice in class from the Practice Exam book.