Відповідь:
1. It is well known that playing sports helps to strengthen health. 2. It turned out that my friends were completely unaware of my arrival. 3. The Mayor himself is expected to participate in the opening ceremony of the new University building. 4. It is said that the Pyramids of Giza contain many more unsolved mysteries. 5. Don't be angry, he will definitely return all your books.
Пояснення: