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.

Imagine traveling at half the speed of a jet plane without ever leaving the ground! Students will discover the technology that makes such speeds possible, from special tracks and safety precautions to aerodynamically designed trains. What are the limits to the speed of trains? What imposes those limits? Students also will read about the future of passenger train travel, from flying trains to trains that use huge magnets to levitate inches or centimeters off the track. Some trains safely reach speeds of more than 200 mph!

Introduces students to the alphabet and letter sounds and helps improve their Spanish-language skills.

Seis títulos componen esta original colección, que recrea emotivas historias en las que los protagonistas (animales) hojean un álbum de fotos en el que pueden rememorar los momentos más entrañables de su vida en familia. Estos libros invitan a los niños y niñas a coleccionar dibujos, fotografías... para imitar al personaje, desarrollando de esta manera una actividad muy creativa e interesante para su desarrollo emocional. Concha López Narváez, autora consagrada y merecedora de numerosos premios, ha escrito los textos. Las ilustraciones de Rafael Salmerón reflejan, con gran calidad...

How do architects and contractors use math and geometry to help build a house? Readers will find out in this engaging, Spanish-translated nonfiction book that features bright images and charts, informational text, and intriguing facts that will familiarize children with construction, construction equipment and materials, and blueprints. This 6-Pack includes six copies of this title and a lesson plan.