PROFICIENCY TESTBUILDER Another title in this popular series of 'Tests that teach', designed to help improve students' exam performance and increase language. COMPACT ADVANCED 2015 Compact Advanced provides C1-level students with thorough preparation and practice of the grammar, vocabulary, language skills, topics Paperbuff said. If you are referring to the PDO files, you need to install Pepakura Viewer to open them. Check the Download Links on the right sidebar. Materials to help your students prepare for the Cambridge English: Proficiency (formerly CPE - Certificate of Proficiency in English). This section features extensive practice materials and articles for the main suite of Cambridge English Qualifications (formerly known as Cambridge ESOL exams.