This site houses a large number of very brief audio files in which native speakers say brief, useful, every day phrases in a number of conjugations. Phrases include things like "How much is this?" "How are you?" or simply reciting useful vocabulary and also cover numbers and time. Each phrase is spoken in 8 or 9 dialects from the regions of North Africa, the Levant, and the Persian Gulf. Every phrase is accompanied by a transcript.

This patient education program explains what colon cancer is, the symptoms, diagnosis, and available treatment options. This is a MedlinePlus Interactive Health Tutorial from the National Library of Medicine, designed and developed by the Patient Education Institute.

Empire, imperialism, and colonialism are all interrelated tactics of geopolitics that are used to achieve similar goals of one state maintaining economic, political, or even cultural dominance over other territories. Today, we’re going to unravel the impacts of colonialism at different times throughout history from Taiwan to Myanmar as we examine the longstanding impacts of these relationships. We’ll also take a look at how some countries today, like Thailand, have taken the control of the narrative through culinary colonization.

In this video segment from Nature, scientists work to discover why bees are disappearing.

This art history video discussion looks at the Colosseum (Amphitheatrum Flavium), c. 70-80 C.E., Rome.

This patient education program explains colostomy and ileostomy and requisite postoperative care. This is a MedlinePlus Interactive Health Tutorial from the National Library of Medicine, designed and developed by the Patient Education Institute.

Over the last four episodes, we’ve examined some of the stories that make up the idea of a “revolution” in knowledge-making in Europe. But we can’t understand this idea fully, without unpacking another one—the so called Age of Exploration. This encompasses a lot of events that happened from 1400 through the 1600s and were driven in part by new ideas about knowledge-making.

In which John Green teaches you about the changes wrought by contact between the Old World and the New. John does this by exploring the totally awesome history book "The Columbian Exchange" by Alfred Crosby, Jr. After Columbus "discovered" the Americas, European conquerors, traders, and settlers brought all manner of changes to the formerly isolated continents. Disease and invasive plant and animal species remade the New World, usually in negative ways. While native people, plants, and animals were being displaced in the Americas, the rest of the world was benefitting from American imports, especially foods like maize, tomatoes, potatoes, pineapple, blueberries, sweet potatoes, and manioc. Was the Columbian Exchange a net positive? It's debatable. So debate.

Chapters:
Introduction: The Columbian Exchange
Diseases of the Columbian Exchange
John Green Does the Cinnamon Challenge (Ew)
An Open Letter to Tobacco
Animals of the Columbian Exchange
Plants of the Columbian Exchange
People of the Columbian Exchange
Credits

In which John Green teaches you about the beginning of the so-called Age of Discovery. You've probably heard of Christopher Columbus, who "discovered" America in 1492, but what about Vasco da Gama? How about Zheng He? Columbus gets a bad rap from many modern historians, but it turns out he was pretty important as far as the history of the world goes. That said, he wasn't the only pioneer plying the seas in the 1400s. In Portugal, Vasco da Gama was busy integrating Europe into the Indian Ocean Trade by sailing around Africa. Chinese admiral Zheng He was also traveling far and wide in the largest wooden ships ever built. Columbus, whether portrayed as a hero or a villain, is usually credited as the great sailor of the 15th century, but he definitely wasn't the only contender. What better way to settle this question than with a knock-down, drag-out, no holds barred, old-fashioned battle royal? We were going to make it a cage match, but welding is EXPENSIVE.

Chapters:
Introduction
Notable Sailors of the 15th Century
Zheng He, Chinese Admiral
Reasons for China's 15th Century Naval Expeditions
Vasco da Gama, Portuguese Explorer
Vasco da Gama's Motivations and Strategies
Myths about Christopher Columbus
An Open Letter to the Line of Demarcation
Christopher Columbus's First Voyage
Who Was the Greatest Mariner of the 15th Century?
Credits

This week we're continuing our discussion of William Shakespeare and looking at his comedies and romances. As well as something called problem plays. Some of his plays, they had problems. We'll also put on pants, escape to forest, and talk about Shakepeare's heroines, lots of whom had quite a bit more agency in these plays than the women in the tragedies had.

Today on Crash Course Astronomy, Phil explains comets. Comets are chunks of ice and rock that orbit the Sun. When they get near the Sun the ice turns into gas, forming the long tail, and also releases dust that forms a different tail. We’ve visited comets up close and found them to be lumpy, with vents on the surface that release the gas as ice sublimates. Eons ago, comets (and asteroids) may have brought a lot of water to Earth -- as well as the ingredients for life.

Chapters:
Introduction: Comets
Comets = Dirty Snowballs
Comets Have Two Tails
Short-Term vs Long-Term Comets
Where do comets come from?
Comets Up-Close
What Happens When Comets Hit Earth?
Review

We've been talking a lot about kings, and queens, and wars, and religious upheaval for most of this series, but let's take a moment to zoom out, and look at the ways that individuals' lives were changing in the time span we've covered so far. Some people's lives were improving, thanks to innovations in agriculture and commerce, and the technologies that drove those fields. Lots of people's lives were also getting worse during this time, thanks to the expansion of the Atlantic slave trade. And these two shifts were definitely intertwined.

In which John Green teaches you about China's Revolutions. While the rest of the world was off having a couple of World Wars, China was busily uprooting the dynastic system that had ruled there for millennia. Most revolutions have some degree of tumult associated with them, but China's 20th-century revolutions were REALLY disruptive. In 1911 and 1912, Chinese nationalists brought 3000 years of dynastic rule to an end. China plunged into chaos as warlords staked out regions of the country for themselves. The nationalists and communists joined forces briefly to bring the nation back together under the Chinese Republic, and then they quickly split and started fighting the Chinese Civil War. The fight between nationalists and communists went on for decades and was interrupted by an alliance to fight the invading Japanese during World War II. After World War II ended, the Chinese Civil War was back on. Mao and the communists were ultimately victorious, and Chiang Kai-Shek ended up in Taiwan. And then it got weird. Mao spent years repeatedly trying to purify the Communist Party and build up the new People's Republic of China with Rectifications, Anti Campaigns, Five Year Plans. the Great Leap Forward, and the Cultural Revolution. These had mixed results, to say the least. John will cover all this and more in this week's Crash Course World History.

Chapters:
Introduction: China's Revolutions
Calls for Reform in China
An Open Letter to Sun Yat Sen
Overthrowing the Qing Dynasty
The Guomindang and the Chinese Communist Party
Mao Establishes the People's Republic of China
China's Soviet-inspired Five Year Plans
China's Cultural Revolution
Credits

Interactions between species are what define ecological communities, and community ecology studies these interactions anywhere they take place. Although interspecies interactions are mostly competitive, competition is pretty dangerous, so a lot of interactions are actually about side-stepping direct competition and instead finding ways to divvy up resources to let species get along. Feel the love?

Chapters:
1) Competitive Exclusion Principle
2) Fundamental vs. Realized Niche
3) Eco-lography / Resource Partitioning
4) Character Displacement
5) Mutualism
6) Commensalism

Hank gets to the more violent part of community ecology by describing predation and the many ways prey organisms have developed to avoid it.

Chapters:
Herbivory and Parasitism
Predatory Adaptation
Cryptic Coloration
Mullerian Mimicry
Batesian Mimicry

Community ecology is the study of interactions between different species of living things, and lets ecologists examine the effects of predator-prey relationships, parasites, and mutually beneficial interactions. In this episode of Crash Course Biology, we’ll examine the myriad interspecies interactions with examples, see how keystone species impact their environment and explore how communities rebuild when they are disrupted, through the lens of the 1980 eruption of Mount St. Helens.

Chapters:
Community Ecology
Community Disturbances
Interspecies Interactions
Competition
Community Regulation
Review & Credits
Credits

Hank introduces us to comparative anatomy, which studies the similarities and differences in animal anatomy to support the theory of evolution and the shared ancestry of living things.

Chapters:
1) Comparative Anatomy
2) Locomotion
3) Heterotophy
4) Convergent Evolution
5) Biolography
6) Tissues
a) Epithelial Tissue
b) Connective Tissue
c) Muscle Tissue
d) Nerve Tissue
7) Organs
8) Organ Systems
Review

The foundation of this lesson is constructing, communicating, and evaluating student-generated tables while making comparisons between three different financial plans. Students are given three different DVD rental plans and asked to analyze each one to see if they could determine when the 3 different DVD plans cost the same amount of money, if ever. (7th/8th Grade Math)

The CyberSquad proves that the area of Hacker's land is equal to the area of Judge Trudy's land in this video segment from Cyberchase.

Watch a video that explains how to write a comparison/contrast essay. Print a document to accompany the video for more practice. Comparison/contrast essays help you learn really efficiently, because they present information in a way our brains like. When we see something new, we want to know how it's similar to something we already know about, and how it's different, too. Let's say that you need to buy a car. When you look at the different models, you'll compare what's similar and different between the models. When a cell phone manufacturer comes up with a new model, they tell you what great features the phone has that people have liked before (the similarities) and what fantastic new features it has that help it stand out (the differences).