If you are a student, a teacher, or a self-learner navigating the Cambridge English B1 Preliminary (PET) exam landscape, you have likely encountered the phrase Published by Macmillan Education, the Optimise series is one of the most popular methodical courses for teenagers and young adults preparing for the revised Cambridge exams.
Now, instead of re-reading the PDF, you are doing active recall on your phone during your commute. This is peak optimization.
Use a PDF splitter tool (like PDFsam – free).
If your Optimise B1 file is a scanned image (e.g., photos of pages), you cannot search for specific grammar terms like "present perfect continuous."