Agujeros negros (Black Holes)

For many years, people believed there were nine planets that orbited the sun. Now we say there are eight. What happened to the ninth planet, Pluto? What are the different planets like? What exactly makes a planet a planet? These are the many intriguing questions answered with this high-interest book, crafted to be accessible for readers of all levels. Young astronomers will be especially fascinated by the stunning photographs and the "Make the Grade" fact boxes.

The asteroid belt between Mars and Jupiter is an intriguing area of our solar system. Scientists have counted over 670,000 known asteroids there, but there could be millions more not yet found. Readers will discover much more about the asteroid belt in this highinterest book, which blends science and math. They'll read about several topics, such as space missions to the asteroid belt and the difference between an asteroid and a planet, and solve associated math problems-just like actual space scientists do!

Fiel a su cita, llega una nueva entrega de Los chistes más morrocotudos de Geronimo Stilton. En este caso, Geronimo y compañía han recopilado los mejores chistes sobre animales: más de 500 chistes nuevos para partirse de risa... palabra de Stilton, Geronimo Stilton. ¡No te los puedes perder!

La conjugación alcohol y adolescencia es una preocupación constante que aparece cíclicamente en el interés social. En algunas ocasiones se visibiliza como un problema de orden público, en otros se acentúa como un problema educativo, en otras ocasiones coge fuerza la visión de salud pública. Todas son ciertas, pero parciales e incompletas si no se aúnan todas las visiones en una interpretación más omnicomprensiva del fenómeno del consumo de alcohol juvenil. Ello es especialmente necesario cuando se trata de buscar soluciones o programas preventivos de impacto en la población...

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.