10 cosas que puedes hacer para ahorrar electricidad

El mundo es el lugar en el que vivimos, pero el mundo es mucho más que eso. Si el mundo únicamente fuera esta tierra, no habría mucho más que vencer que asegurarnos de no ahogarnos en el río o en el océano, o asegurarnos de no caernos de un árbol alto. ¿Por qué debemos vencer al mundo? ¿Por qué habría yo de necesitar vencer al planeta tierra? ¿No es el mundo simplemete la tierra que Dios creó? Estas son las preguntas que podríamos hacernos de manera genuina después de leer el versículo en 1 Juan 5:5. Quizás no lo comprendamos, pero la Escritura es muy clara en cuanto a que...

Mathematics constitutes ideal material for exercising the art of learning and thinking. For this it is necessary that the classroom has a stimulating atmosphere which requires determined attitudes and beliefs. The book combines theory and practice and responds to questions such as these: to think in the mathematics class? on what does the knowledge of solving problems really consist of? what are the beliefs and which are the most common ones among the students? how to diagnose, evaluate and, in some cases to modify, the systems of beliefs of the pupil?).

Examines the apparent connection between birds and dinosaurs by comparing fossils, dinosaur bones, and modern birds.

The Underground Railroad was the massive effort by slaves and free people to secretly bring thousands of blacks to freedom in the North during the 19th century. This thought-provoking book will capture readers’ imaginations and fill them with awe for the brave “conductors” and “passengers” on the Railroad. They’ll learn about the many safe havens, called “depots,” that housed fugitives and the secret passages within them that hid slaves from their pursuers. Information about the American Civil War and the Fugitive Slave Act, biographies of figures vital to the Underground Railroad,...