Do you think Earth makes fun of other planets for having no life? The presentation covers the rotation and revolution of both the earth and our moon. It provides explanations for seasons, tides, and eclipses. Lesson is the 20th in a...

Get an in-depth look into erosion and deposition with a 23-slide presentation that details how gravity, water, waves, wind, and glaciers cause changes to the Earth's surface. Each slide consists of detailed images equipped with labels,...

Scientists found fossils of plants more than 420 million years old—but plants existed for up to 100 million years prior to these fossils. Learn about the importance of plants to the entire planet. Viewing a presentation helps scholars...