Early readers will love reading simple questions of keen interest (“Is it cold underground?”), guessing the answer, then turning over the flap to reveal a brief answer (“No. The deeper you go underground, the hotter it gets.”). Answers include a realistic illustrative diagram of the related earth science principle. Seven topics: Planet Earth, Air, Life on Earth, The Oceans, Inside our Planet, Earthquakes, Volcanoes. Index. Hardcover, 18 pages plus 7 half-panel flaps.