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.

Pon a prueba tus neuronas con 365 enigmas y juegos de lógica, uno para cada día del año. ¿Te gustan los desafíos? ¿Eres el rey de los enigmas? Abre este libro y prepárate para exprimir tu cerebro con 365 divertidos y estimulantes juegos de ingenio. De la mano del matemático Miquel Capó, descubrirás los mejores acertijos, paradojas, ilusiones ópticas y problemas matemáticos. ¡El entretenimiento está asegurado!

Transcripción de debates entre dos Testigos de Jehová en discusión abierta contra un ateo, grabados con cámara oculta.

Families can be big or small, but all resemble each other in one aspect: they have a past and a present that, is also part of a broader history, that of a culture or race, or that of the world. The reader will see that family trees are used both by historians and everyday people who trace generations of relatives. Although family trees imply blood relations, the ties of love and friendship are often just as important.

This guide gathers a selection of more than 500 species of vertebrate animals cataloged and arranged in colored illustration. It is an exhaustive and complete guide that provides precise information about each species, and that captures all the beauty and diversity of the vertebrate world in spectacular design and with enthralling visuals.