Ideal books are the key to wisdom. ——Tolstoy, books are the ladder of human progress. ——Gorky.

The ideal book is the key to wisdom: The famous saying "Book is the key to wisdom" was written by Tolstoy, which compares the book to a key, opening the door to wisdom and knowledge.

Books are the ladder of human progress: The famous saying "Books are the ladder of human progress" was written by Gorky, which compares books to ladders, leading to the road to progress.