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.

This Title Explains What An Ecosystem Is And How The Plants And Animals Within An Ecosystem Rely On And Effect Its Existence. Different Types Of Ecosystems Are Described, As Well As The Food Webs Within Them. How Some Changes To An Ecosystem Can Be Good And How Some Harmful Changes Can Destroy Them. Teaches Students What An Important Role They Can Play In Keeping These Intricate Ecosystems Alive.

Amusing And Engaging Text Describes How The Color Of An Animal Can Ensure Its survival. Provides Examples Using A Variety Of Animals.

En este diccionario ilustrado para niños Clifford, el gran perro colorado, y sus amigos describen cada palabra por medio de oraciones sencillas. Incluye una sección especial sobre los números, los opuestos y mucho más.

Where Do You Come From? Learn About Heritage And How To Build Your Own Family Tree. Social Studies Based Leveled Readers For Use In Guided Reading And Social Studies Instruction.