El magnetismo (Magnetism)

The US president is the face of the United States to the rest of the world. However, he or she doesn’t have unlimited power within the country. The president has certain powers given by the Constitution, including the ability to make treaties, appoint some important government officials, and veto laws. Readers learn the many duties of the president in simple, clear language appropriate for both younger readers and older readers looking for a succinct review of the topic. Fact boxes supplement the main content with important details about checks and balances, amendments, and more that affect...

Newton's laws aren't the easiest science topics to digest. Struggling readers likely find understanding them even harder. This volume breaks down the topics of force and motion to its most basic and understandable parts, perfect to introduce to readers having a hard time or students looking to review for class. Written in succinct language, each chapter contains fact boxes and graphic organizers to aid all readers as they move from speed, to velocity and on.

¿Por qué perdimos la guerra? analiza de forma clara y detallada las razones que llevaron al ejército republicano a la derrota en la Guerra Civil española. Carlos Rojas presenta una completísima obra que incluye una antología con los testimonios de muchos de los vencidos en la contienda española.La obra se compone de seis apartados con las diferentes interpretaciones de las causas que motivaron la catástrofe republicana, en un conflicto que Stanley Payne llamó, y con razón, «la mayor tragedia de la historia española después de la Guerra de la Independencia». Una obra capital que...

Rabbit burrows play an important part in the life of a rabbit. A burrow provides a place to live, a place to raise baby rabbits, and a place to stay safe from predators. This volume, which was written to support elementary science curricula, examines the role a burrow plays in the survival of a warren, and how that in turn helps rabbits contribute to ecosystems around the world. The text’s age-appropriate, science-rich content focuses on rabbit behavior and encourages readers to draw connections between what they learn in science class and what they see outside. This text is complemented by ...

Pocas personas han alcanzado el nivel de inteligencia que tuvo este hombre, ninguna de ellas ha sido tan importante para la humanidad y el mundo contemporáneo, como él. Considere Ud. que, sin este personaje y sus teorías sobre la relatividad y el tiempo, jamás podrían haber existido objetos como celulares o computadores... Por nombrar los dos más usados inventos actuales. Y, aunque suspendió el examen de ingreso en la Politécnica, la revista Time le nombró "personaje del siglo XX", seguramente porque sus aportaciones a la física revolucionaron los conocimientos de la era...

Most young astronomers know that Earth is located in the Milky Way galaxy, but they might not know what that means or what lies beyond. Understanding our galaxy and others will help them comprehend more about how the universe works. Your readers will discover many amazing and memorable facts about galaxies, including their differing shapes, numbers of stars, and constant movement. They'll especially love the mind-boggling images of the depths of space.