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

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.

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.

El mundo natural es un lugar extraño donde ocurren las cosas más insólitas y sorprendentes. Récords, curiosidades y extravagancias reunidas por temas: botánica, animales salvajes, domésticos, acuáticos, reptiles, insectos, aves, dinosaurios y fenómenos naturales, para enterarse de que el sauce enano no pasa de los 6 cm de altura, que los dientes del hipopótamo pueden llegar a medir medio metro, que el camello puede beber hasta 150 litros de agua de una sola vez, que el cocodrilo puede aguantar la respiración bajo el agua una hora... ¡lee y descubre!

A 2014 report by the US Department of Education found that 22 percent of students ages twelve to eighteen had experienced bullying. This cogent narrative provides readers with supportive methods to help a friend who is being bullied and to promote a bully-free learning environment at school. Physical, social, psychological, and verbal bullying are examined, as well as cyberbulling. Readers discover the consequences of bullying both as a target and as a bystander. They also consider ways to intervene in a bullying situation, how to seek adult help, and how to be empowered and recover from...

"Ha pasado más de un año del desenlace de "Nadie ha muerto en la catedral". Rebeca Turumbay no ha vuelto a ponerse en contacto con sus amigos de Cárcar y se ha refugiado en Florencia, donde estudia restauración de arte renacentista. Por su parte, Víctor Yoldi se ha trasladado a Pamplona para trabajar en el Diario de Navarra. Cuando se le presenta la oportunidad de escribir un artículo sobre la cárcel recién inaugurada, aprovecha para visitar a Jonás Sádaba, que sigue en prisión desde la muerte de su madre, y para llevarle recuerdos de todo Cárcar. Jonás está preocupado, ya que...

Addresses questions kids often wonder about, where there is usually no simple answer, offering different theories and opinions with examples and comparisons.