La antigua Roma (Ancient Rome)

Wind Power: A waving flag, blowing leaves, a kite soaring through the skyall are moved by wind power. Wind is also our fast-growing source of energy. Find out how wind forms and the different ways we may use it in the future.

Una guía para sobrevivir a la adolescencia masculina, sin morir en el intento. Confidencial Contiene información valiosa para todas aquellas víctimas de la epidemia adolescente y sus síntomas más notorios: invasión de pelos y acné, neuras inmanejables, contradicciones crónicas, insomnios frecuentes, bronca escolar implacable, amoríos platónicos, resistencia pasiva, enmudecimientos prolongados y ¡desesperación familiar! Con un tono directo y sin prejuicio, este libro busca orientar y dar respuesta a temas difíciles como los músculos, los deportes, las mujeres, el acné, datos...

This beginner's guide offers a first glimpse into the natural world of amphibians. This addition to the acclaimed About... series uses simple, easy-to-understand language to teach younger children what amphibians are, how they look, how they move, what they eat, and where they live. With beautifully detailed, realistic paintings, noted wildlife illustrator John Sill introduces readers to a variety of amphibians, from frogs and toads to salamanders and more. An afterword provides details on the animals featured and inspires readers to learn more.

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!

Students will gain a deeper understanding of the Cold War by delving into major social studies topics in this project-based examination. The volume presents a series of broad questions touching on major themes in the social studies curriculum. Each question is accompanied by several paragraphs examining that question in the context of the Cold War, as well as a detailed project that prompts readers to think critically and present their findings or opinions in a particular format, such as a poster with side-by-side comparisons, a persuasive essay, or a class presentation.