A level 3 Oxford Bookworms Library graded reader. This version includes an audio book: listen to the story as you read. Written for Learners of English by Alex Raynham. You're fast asleep, and nothing is happening. Or is it? In fact, your body is hard at work. Your lungs are taking oxygen from the air, and your heart is pumping blood round your body. Millions of pieces of information are travelling backwards and forwards to your brain all the time. Muscles are repairing themselves, and in your lymph nodes special cells are cleaning germs and waste from the body. You may think that nothing is happening, but in the extraordinary machine that is the human body, it is very busy indeed . . .

A level 3 Factfiles Oxford Bookworms Library graded reader. This version includes an audio book: listen to the story as you read. Written for Learners of English by Tim Vicary. Imagine an animal with teeth as big as bananas – and a brain as big as an orange. Or a flying animal with wings as wide as a small plane. Think about a tail that could knock a man’s head off, or a mouth with hundreds of teeth. Is it any surprise that people are interested in dinosaurs? Nobody has ever seen a living dinosaur, but millions of us go to museums every year to stare at the bones of these enormous animals. In books, films and games, we can’t get enough of the secrets of the dinosaur world . . .