Here are some words to help answer the question "Which one?" We distinguish between singular and plural as well as between something close to us and far away.

We learn more about how water interacts with the minerals in the rocks, and visit Monument Valley, a popular spot for filming westerns and commercials.

Ed Sheeran described this romantic ballad as a "walking down the aisle song." In the video, he executes a ballroom dance with Brittany Cherry, a contestant from the televised American dance competition, So You Think You Can Dance. While on concert tour, Sheeran spent five hours a day for three weeks to practice with Cherry.

Singer-songwriter Meghan Trainor's latest hit connects to the #metoo movement and the problem of men not paying attention to the boundaries set by women.

In this segment, we learn about the role weather plays in the creation of rock formations in the national parks of the United States.

Prince narrates a one-night stand with a beautiful but promiscuous woman (the "Little Red Corvette" of the title). He uses several other automobile metaphors in the song.

This song was written and sung by Bob Dorough. It teaches about the multiplication of 5 through a game of hide and seek, in which the seeker counts by fives.

Watch some coverage of the People's Climate March that was timed to coincide with the UN Climate Summit in New York City. The march was attended by 400,000 people.

Geysers represent a very popular tourist attraction in Yellowstone Park. How do they work and where do they come from? And what is sandstone? The video answers these questions.

“Don't Answer Me” is a song by Alan Parsons and Eric Woolfson, the British duo behind the Alan Parsons Project. This is their first music video, which features an award-winning animation by Michael Kaluta, inspired by 1930s comic strips.

Lindsey Vonn describes her early days on the slopes, the encouragement she received from her father, and coming back from the many injuries she has endured on her way to becoming a champion skier. She also talks about her decision to compete against men in alpine skiing.

The song "Run" is from Irish band Snow Patrol's album "Final Straw." The video features frontman Gary Lightbody in a forest at nighttime.

In Yellowstone Park, visitors can see many indigenous animals in their natural habitat and wonder at the park's natural hot springs.

"China Girl" was originally co-written by David Bowie and Iggy Pop when they lived in Berlin. Although there are many interpretations of the song's meaning, the video particularly looks at and parodies Asian female stereotypes.

Natalie Fee concludes her Ted Talk with a few suggestions for what we can do to reduce how much single-use plastic we are sending into the earth's waterways.