Classics, modern fiction, non-fiction and more. Written for secondary and adult students the Oxford Bookworms Library has seven reading levels from A1-C1 of the CEFR.A human being is a soft, weak creature. It needs constant supplies of air, water, and food; it has to spend a third of its life asleep, and it can''t work if the temperature is too hot or too cold. But a robot is made of strong metal. It uses electrical energy directly, never sleeps, and can work in any temperature. It is stronger, more efficient - and sometimes more human than human beings. Isaac Asimov was one of the greatest science fiction writers, and these short stories give us an unforgettable and terrifying vision of the future.