Planet Earth CrosswordsAuthor Editor: Phillip Clarke Illustrator: Pope Twins Age: 6+ English Page: 112 pages Paperback 19. 8 cm x 113 cm Test your knowledge with over 100 planet earth themed crosswords, covering everything from animals and plants to cities, countries, continents, rivers and mountains. The crosswords gradually get harder throughout the book, and are perfect for quiet times alone or playing with friends and family. All the answers are at the back of the book.