How tall are towers? Who cleans the window of the Burj Khalifa? Find out more about skyscrapers and the science of tall towers.Do You Know? is a series of levelled non-fiction books featuring video content, project work and critical-thinking activities to motivate and engage young learners. Covering a range of STEM topics from nocturnal animals to climate change, Do You Know? takes an enquiry-based approach, developing children's language, communication and investigation skills.Recommended for children aged 7+, there are four levels progressing from CEFR level Pre-A1 to level A2. Each reader is accompanied by online video content, audio, video and comprehension activities, and suggestions for project work. Tall Towers, a Level 1 Reader, is Pre-A1 in the CEFR framework and supports YLE Starters exams. Short sentences contain a maximum of two clauses, using the present tense and some simple adjectives.