¿Por qué hibernan los animales? (Why Animals Hibernate)

The rock cycle has been taking place for millions of years. However, geologists have only known about this phenomenon for about 300 years. Young terrestrial explorers are introduced to different types of rocks, where in the cycle these rocks fit, and where in Earth's layers each step takes place. Fact boxes provide readers with fun additional information. A diagram helps readers make sense of the new information they're learning.

Although Earth is mostly made up of igneous and metamorphic rock, sedimentary rock covers about 75 percent of Earth's land surface. This means it's the most visible kind of rock on Earth. Sedimentary rocks form when sediment accumulates and compacts. Your readers will learn how sedimentary rocks form, the different types of sedimentary rocks, and how people use sedimentary rocks. Fun fact boxes provide readers with additional information. A helpful diagram illustrates how sedimentary rocks form.

When rocks change because of environmental conditions, the new rocks are called metamorphic rocks. A rock's chemical or physical makeup may change because of conditions such as temperature, stress, or pressure. Your readers will learn fascinating facts including where metamorphic rocks are most commonly found, the different types of metamorphism, and how metamorphic rocks are identified. Full-color photographs depict these rocks in nature. A helpful graphic organizer shows how these fascinating rocks form.

Six titles in the illuminating Who Was . . . ? series are now available in Spanish-language editions. Each title features black-and-white illustrations.

When Paul Revere warned colonists the British army was coming, he helped prepare a nation for battle. This exciting book will take readers from Revere’s life as a silver- and goldsmith to his midnight ride at the start of the American Revolution. Through achievable content and language translated into Latin-American Spanish, English language learners will engage with important historical facts and ideas. A helpful timeline of events and colorful images will enhance the story of one of American history’s most famous folk heroes.

Tommy Fuller and his family help a runaway slave family follow the stars in the Little Bear constellation to freedom.

"Si amo a los seres con tanto ardor, es porque en cada uno de ellos amo una parte de ti, Dios mío" Etty Hillesum Han tenido que pasar muchos años para que el mundo descubriera el luminoso rostro de Etty Hillesum. ¿Quién habría creído, en vísperas de la Segunda Guerra mundial, que esta joven judía, locamente enamorada de la vida y aparentemente despreocupada, iba a dejarnos como herencia uno de los testimonios más profundos sobre la entrega de uno mismo y el amor a los seres y a Dios? Nacida en Holanda en 1914, Etty Hillesum es una joven libre, llena de ardor y de curiosidad, que se...