Fundamentos de televisión analógica y digital

Desde la más remota antigüedad las personas han sentido fascinación por la luna, el astro más cercano a nuestro planeta. Los babilonios y los aztecas, por ejemplo, confeccionaron calendarios muy precisos basándose en las observaciones de la luna. Nuestro satélite natural en el momento en que se encuentra más cerca de la tierra está a 365.000 kilómetros de distancia. El estudio de la luna tuvo un gran impulso cuando el gran científico italiano Galileo Galilei inventó el telescopio en 1610 y con ayuda de este instrumento pudo realizar interesantes observaciones que le permitieron...

In the last one hundred years, Earth’s average temperature has risen one full degree. That might not sound like much, but it affects Earth’s oceans, land, plants, and animals. Learn all about global warming, the carbon cycle, the greenhouse effect, and weather and climate with this Spanish science reader that brings the power of science and informational text to students at a level they can understand. This nonfiction book introduces students to new concepts, vocabulary terms, and STEM topics. With detailed images and fascinating sidebars, the leveled text supports students reading at...

Can you find these in the book? robin, tulip. What is your favorite season? Books in the Seasons series explore seasonal changes from a child's point of view. Fin out about the sights, sounds, tastes, and smells that each season brings.

Learn how to help others in your community. This exciting Spanish nonfiction book describes the many ways that volunteers make a difference, from cleaning up parks to helping in food banks. Perfect for young readers, the book includes a short fiction stor