"Вопросы-ответы" is a book that has become a classic of the genre of popular scientific and popular literature. The author of the book, who carefully processed and structured a large number of questions of interest to the reader, provides clear and concise answers to them. Thanks to this book, the reader can quickly find answers to a wide variety of questions: from the simplest to the most complex, from household to scientific. "Questions-answers" is an inexhaustible source of new knowledge and interesting information for everyone who is interested in the world around them and wants to expand their horizons.