On Nov. 11, an Australia horse-rider got hurt after his horse “broke down” during a horse race in Hong Kong. The rider is safe now, but his horse’s leg injury (伤) led to its death. Falling off a horse at high speed has a big risk of injury. You can say it’s the rider’s choice to take part in the sport. But what about the horses?

This is not the first time that animals have been harmed because of animal entertainment-related (与娱乐相关的) sports. For example, about 180,000 bulls (公牛) are killed in bullfights around the world, with many more injured in bullfight events every year, according to Human Society International, a company researching the human-animal relationship. “Hunters shoot more than 800 lions in South Africa,” reported World Animal Protection.

However, some people come to realize how badly animals can be hurt when being trained and used for entertainment purposes. To help these animals, animal lovers have started many protection activities. In June, Churchill Downs, a small town located in the west of the US, stopped all horse racing. Performances using animals have been stopped by many countries around the world in recent years.

Animals play an important part in our lives and are more than tools for sports and entertainment. The human-animal connection can be seen in all kinds of places. Service animals can help people in their jobs and animals are also used to help and care for people with illnesses or who have experienced bad accidents.“We can have our sports, drinks, lively parties and beautiful hats—but we can leave the animals out of it,” reported Vox, journalist from World Animal Protection.

On March 14, math and science lovers around the world celebrated a special day: Pi Day. Pi is equal to about 3.14, but the number goes on endlessly. It is sometimes written as π. With the help of computers, mathematicians have been able to calculate (计算) Pi out to over a trillion decimal (小数) places, but there is still no end to the number. This makes Pi puzzling, even for the most famous scientists and mathematicians. Pi Day is celebrated around the world on March 14, since how we write this date, 3/14, looks just like the number Pi.

For some people, the attraction of Pi Day goes far beyond math and science. Pi shows up throughout popular culture. You can see it in movies, comics, music and more. In modern movies, any time the filmmaker wants to create a sense of mystery, often the symbol Pi is used.

People also love trying to memorize the digits of Pi and competing against others to see who can remember the most. Most teachers hold class contests to see how many numbers their students can memorize. The World Record for reciting (背诵) the most digits of Pi is held by Lv Chao of China, who successfully recited Pi out to nearly 67,890 decimal places.

Above all, Pi Day is about having fun with the number. People celebrate Pi Day by eating or throwing pie and with fun pi-related games and activities. Princeton, New Jersey, used to hold a birthday party for Albert Einstein whose birthday also falls on March 14. There was also a “Walk a Pi Event” where people walked 3.14 miles together. Just like the number itself, the possibilities for Pi Day are truly endless.