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.

"Eran diez los mariachis. Ahora solo quedan nueve. Ay, caramba, ¿qué pasó? ¡La guitarra se rompió! Cuenta hacia atrás con esta simpática banda de diez mariachis."--P. [4] of cover.

Sofía and her friends accuse someone of theft based on his appearance, but when the truth comes out, they learn a lesson about passing judgment based on superficial traits.

Defines levers, explains their functions, and suggests simple experiments to demonstrate how they work.

What's the best way to keep the body and mind healthy? This book explores helpful ways to keep bodies in good shape and brain strong as well as the importance of being happy. The language arts connection is important vocabulary about staying healthy.