70 preguntas curiosas sobre el mundo que nos rodea y sus asombrosas respuestas

Biología sin pérdida de tiempo, para maestros y alumnos con prisa, volúmenes I y II, son libros electrónicos creados por médicos y biólogos ampliamente calificados, que han dedicado su vida a la docencia y la investigación. La finalidad de estos libros es proporcionar al docente contenidos sintetizados del programa de biología, libres de información superflua o baladí. Además, incluyen un extenso banco de preguntas con respuestas de opción múltiple, que permiten preparar exámenes con sólo copiar y pegar los reactivos elegidos, así como calificarlos con mucha rapidez, lo cual...

Learn the history of number systems with this engaging Spanish book! This text combines mathematics and literacy skills, and uses practical, real-world examples of problem solving to teach math and language arts content. Students will learn place value while reading about the number systems of the Egyptians and Romans, and also learn important vocabulary terms like cuneiform, binary systems, roman numerals, and more! The full-color images, math charts, and practice problems make learning math easy and fun. The table of contents, glossary, and index will further understanding of math and...

¿Un concurso de héroes? Morris y sus amigos tienen que ir al bosque de Zorris para ganar el antifaz de oro, pero ¡te necesitan! En el camino tendrás que resolver sudokus, descifrar códigos secretos, contar chistes, jugar al escondite e incluso hacer tu pr

It was September 14, 1814, and America and Great Britain were at war. Frances Scott Key watched from the deck of a British ship, where he was being held captive, as cannons exploded around them. After 25 hours, the fighting ceased and Key peered through the clearing smoke, looking for some sign as to the outcome of the battle. Was the American flag still flying? His wartime experience inspired Key to write a poem, which was later set to music and became America’s national anthem. This book tells the story of the inspiration behind our national anthem, which helped transform the flag into a...