Maria Zef

The US president is the face of the United States to the rest of the world. However, he or she doesn’t have unlimited power within the country. The president has certain powers given by the Constitution, including the ability to make treaties, appoint some important government officials, and veto laws. Readers learn the many duties of the president in simple, clear language appropriate for both younger readers and older readers looking for a succinct review of the topic. Fact boxes supplement the main content with important details about checks and balances, amendments, and more that affect...

El mundo de los libros es un mundo casi de otro mundo. Un mundo propio, mundo único, un mundo sostenido por el tenue hilo de una inspiración y un sujeto inspirado. Pero “el libro” posee en su interior big bangs semánticos que no paran de generar universos por doquier. Universos donde viajar, donde aprender, donde disfrutar y donde perderse. En esta breve obra hablaremos en primer lugar del libro. Qué es, cómo se concibe y, sobre todo, como es percibido por doctos e indoctos. Luego pasaremos a examinar de cerca a aquellos que aman tanto los libros que sufren una enfermedad de afecto...

There are many steps in the nitrogen cycle that include difficult concepts and words: denitrification, prokaryotes, ammonia, and more. With the help of this understandable book, even struggling readers will grasp this cycle of nature. Low-level language, fact boxes, and an extended glossary provide readers with essential vocabulary explanations that allow them to further understand each step of the cycle. Full-color diagrams aid readers' comprehension as they move through the cycle from start to finish, and then around again.

Learn more about the renowned British scientist, professor, and author who spent his entire career trying to answer the question: "Where did the universe come from?" Stephen Hawking was born exactly three hundred years after the death of the scientist Galileo, so maybe it was written in the stars that he would become a famous scientist in his own right. Although he was diagnosed with a neurological disease at age 21, Stephen did not let the illness define his life. Known for his groundbreaking work in physics, and identified by his wheelchair and computerized voice system, Stephen continued...