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Friday was World Photo Day. According to World Photo Day's website, August 19 is the day the photographic process known as the Daguerreotype was patented in 1839.

The first World Photo Day was in 2009.

World Photo Day allows people to "celebrate their passion for photography."

On World Photo Day, many people are posting their favorite photos with the hashtag #worldphotoday. That includes photos from the Rio de Janeiro Olympics.

One photo many people liked came from the qualifying part of the men's 200-meter race. Sprinter Usain Bolt of Jamaica was pictured smiling as he crossed the finish line ahead of the other runners.

Many people wondered how photographers were able to catch such an image.

Many wrestlers lift their coach up onto their shoulders instead. But do not worry, Kawai did that, too.

Earlier in the week, another image from Rio caught the world's attention. During a 5-kilometer race, American runner Abby D'Agostino and Nikki Hamblin of New Zealand had an accident. The runners' feet touched and both athletes fell to the ground.

Both Hamblin and D' Agostino looked hurt. But they helped each other up and kept running. It turned out D' Agostino had a severe knee injury. She crossed the finish line far behind the other runners. D' Agostino was not able to continue in the Olympics.

Many people said the picture of the two women helping each other up was the perfect example of the Olympic spirit.

Another dramatic moment came in the women's 400-meter race. Allyson Felix of the United States was in the lead with just a few meters to go. But at the last second, Shaunae Miller of the Bahamas dove over the finish line to win the gold medal.

Miller's dive was legal, and she became the Olympic champion.

Of course, no World Photo Day would be complete without people sharing photos of their cats. So here is a photo of a cat in bed.

And that's What's Trending Today.

I'm Dan Friedell.

Dan Friedell wrote this story for Learning English. Jill Robbins was the editor.