Tác giả: Mariel Bard

Amphibian fossils tell us a great deal about the frogs, toads, salamanders, and other amphibians that lived on Earth thousands and millions of years ago. With every turn of the page, young fossil …

Air moves in large bodies called air masses. When two air masses bump into each other, the place where they meet is called a front. This is where weather often occurs. This fact-filled book explores …

Elected officials have a duty to represent and advocate for the values of those who elected them. Most politicians align themselves with one of two political parties: Republican or Democratic. But …

Our planet contains a great deal of heat under its surface. Scientists have learned how to tap into this heat and use it as an alternative energy source. This book brings students inside Earth for an …

Establishing accurate self-perception can help children, teachers, and parents identify not only areas of excellence but also areas in need of more attention. This book guides young readers in …

One of the single greatest leaps forward in human healthcare happened because of an accident in a laboratory. This serendipitous event was the result of a summer vacation in Scotland and an …

Deep underground, below the bustling streets of cities big and small all around the world, subway trains shuttle passengers to their destinations. From the world’s oldest subway in London, built in …

High above our heads, orbiting Earth, are huge technical wonders called satellites. These instruments do so much for us, from helping our cars navigate through GPS to informing meteorologists’ …

No longer are sports played only on a field or in an arena. Professional gaming leagues are gaining worldwide recognition for their exciting competitions and star players, most of whom rose to fame …

Our solar system would fall apart without the sun. Its gravity is what keeps planets and other celestial bodies moving in orbit. The sun also plays a big role in Earth’s weather, climate, and …