Who Was Stephen Hawking?

Tornadoes are some of the strongest storms on the planet. It’s not safe to go near them, but what if we could? Readers will dive into the world of wild weather in a special ship that lets them get up close and personal with a tornado. From the cone of silence deep inside the storm to the incredible winds and lightning created by a superstorm, this book will electrify readers as well as educate them on what to do if a tornado forms nearby.

Siervos medievales presenta una realidad social poco estudiada hasta ahora por la historiografía medievalista: la vasta extensión de la dependencia campesina de carácter servil en el norte de la Península y, en especial, en Aragón y Navarra, durante los siglos XI al XIII. Indaga la experiencia vital de los siervos, las características de la reproducción social de las familias serviles y la dinámica de la dominación ejercida por los señores. Muestra la ambigüedad de los estatutos, del deshonor que pesaba sobre los siervos y las características de la resistencia campesina. El...

Enseña a los jóvenes a través de los mensajes que los hombres más sabios del mundo han dedicado a la juventud a disfrutar plena y responsablemente de lo que otorga la naturaleza.

Muddy Creek in Edgewater, Maryland is the site of a major makeover. The land around the stream has worn down. Find out what caused Muddy Creek to erode, and the many steps involved in saving it. Created in collaboration with the Smithsonian Institution, this Smithsonian Informational Text builds students' reading skills while engaging their curiosity about STEAM topics through real-world examples. It features a hands-on STEAM challenge that guides students through every step of the engineering design process, from the initial research and brainstorming sessions, through the design and testing ...