The impact of natural disasters is made vivid in this video segment adapted from NOVA. A small town in Iceland, prepared for recurrent avalanches, is devastated when one takes a new and damaging path.

In this video segment from TV411, figure skaters compute their average daily practice time.

In this video from DragonflyTV, Jai and Jonathan track, graph, and analyze the motion of basketball shots as they investigate what factors influence the accuracy of their game.

This audio excerpt captures the beginning of Bayard Rustin's 1967 "Freedom Budget" speech, describing the social and economic impact of racism over time.

This audio excerpt from Bayard Rustin's 1967 "Freedom Budget" speech outlines a nine-year plan to end poverty in America.

This Nature video segment focuses on the four foods most important to the grizzly bears' survival, and it describes the threats to the supply of each of them.

In this video segment from Nature, learn about the problems bears are creating on ranch land surrounding Yellowstone National Park.

This Nature video segment explores how the relationship between humans and grizzly bears has changed over the course of American History, and it describes the closing of the Yellowstone National Park garbage dumps in the 1970s.

Learn about the precautions humans must take in the face of a growing grizzly bear population in this video from Nature.

This video segment explores the world of the beaver, including the biology of the species and, more importantly, its ability to transform an ecosystem for its own benefit.

This video segment describes how the Australopithecus afarensis skeleton known as Lucy could have been fossilized. Footage courtesy of NOVA: "In Search of Human Origins."

This video segment from NOVA: "The Mystery of Animal Pathfinders" explores honeybee communication and navigation.

Cocos Island, a remote volcanic summit in the middle of the Pacific Ocean, serves as a beacon for hungry predators, including thousands of hammerhead sharks that travel here each year in search of prey. This video segment from NOVA: "Island of Sharks" depicts some of the common predator-prey interactions that take place in the nutrient-rich waters surrounding the island.

Bianca visits a bike shop and learns how bicycle gears work in this Cyberchase video segment.

This Cyberchase video segment features Bianca, who must figure out the fastest route to a movie premiere.

This video segment from Cyberchase introduces the idea of inverse operations as Bianca imagines herself as a spy.

This video segment from Evolution: "Extinction!" shows the impact of invasive species on native ecosystems.

This ZOOM video segment shows how to create a self-contained environment and explores evaporation, condensation, and precipitation.

This interactive resource adapted from NASA describes the different temperature, precipitation, and vegetation patterns in seven biomes: coniferous forest, temperate deciduous forest, desert, grassland, rainforest, shrubland, and tundra.

There are almost as many types of bird beaks as there are types of food that birds like to eat. This collection of images shows a wide range of beaks and the types of foods handled by each.