Exploremos el ciclo de la roca (Exploring the Rock Cycle)

When winter hits, many people in colder climates spend most of their time indoors. But what do wild animals do? Some animals spend winters hibernating. Beginning readers will learn what hibernation is, why some animals hibernate and others don't, and how hibernating animals prepare for their long sleep. Full-color photographs grab readers' attention and allow them to draw connections to the narrative. Readers will love learning about this mysterious, restful time in some animals' lives.

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.

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.

Who were the earliest Americans? When, how, and from where did they enter and spread across the continent? And what is their relationship to modern Native Americans? Anthropologists develop theories to answer these questions based on the evidence they discover. Their theories—and the discoveries that prove and disprove them—are highlighted in this fascinating volume, full of awe-inspiring facts and incredible breakthroughs. Readers will feel like anthropologists and archaeologists themselves as they read about bones and artifacts, and what they reveal about the ancient cultures that roamed...

Simple text and photographs describe the life of Michelle Obama. Michelle Obama became First Lady on January 20, 2009. But before she lived at the White House, she was a powerful lawyer. Learn about her childhood, education, and goals as first lady of the United States.

Colección infantil de la psicóloga Andrea Cardemil sobre el control de emociones en niños y niñas. Todos los niños y niñas a veces sienten miedo. A Filipo le da miedo los ruidos fuertes, a Benito la multitud, y a Amelia hacer algo por primera vez. Descubre cómo logran sentirse seguros para enfrentar la situación.

Many insects hatch from eggs and molt several times as they grow bigger. Others, such as butterflies, undergo a complete metamorphosis. A common science curriculum topic, insect life cycles may be confusing because of these differences. However, this book breaks down these cycles into easy-to-understand steps in both accessible language and colorful diagrams readers can turn to for review again and again. The most important vocabulary needed to talk about insect life cycles is further explained in fact boxes and an extended glossary.