Class examples (these will all get 10 points!):

Please vote on these:

5. [[Bullying is Wrong]]

6. [[Spirited Away]]

7. [[How Coronavirus has Changed our Lives]]

8. [[The Importance of English]]

14. [[Which is more effective, online or face-to-face class?]]

17. [[Smoking and Drinking]]

22. [[Nutrients]]

23. [[Young people voter turnout problem in Japan]]

24. [[About the Working Environment in Japan]]

25. [[Integrated Junior High and High School]]

26. [[Smoking in Public]]

2. [[Paper books or Electronic books]]

25. [[Classes Online or Face to Face?]]

8. [[Bullying is Wrong]]

9. [[Spirited Away]]

10. [[How Coronavirus has Changed our Lives]]

11. [[The Importance of English]]

12. [[Holding of the Tokyo Olympics]]

13. [[Working at a Convenience Store]]

14. [[Why is Iphone Popular?]]

15. [[My Track and Field Life]]

16. [[Problems with the Coronavirus Vaccine Rollout]]

17. [[Which is more effective, online or face-to-face class?]]

18. [[Japanese School Uniforms]]

19. [[The Relationship between Work and Happiness]]

20. [[Smoking and Drinking]]

21. [[Protecting Kumamoto]]

22. [[Café au lait vs Caffe Latte]]

23. [[Phone is better than Email]]

25. [[Smartphones vs landline telephones]]

26. [[Nutrients]]

27. [[Young people voter turnout problem in Japan]]

28. [[About the Working Environment in Japan]]

29. [[Paper books or Electronic books]]

1. [[Betelgeuse: A Future Supernova Explosion]]

Do you like to look at the stars? They shine like jewels and heal us. Looking up at the sky on a winter night, you can see a characteristic constellation. It is Orion. Three consecutive stars are the characteristic configuration of this constellation. However, look at the only red glowing star in the upper left. The star is named Betelgeuse and is the second brightest star in Orion. It also forms the Winter Triangle. It shines brightly every day, but it may explode in the near future.

Why is Betelgeuse red? That’s because Betelgeuse is an old star. Stars also have a lifespan like living things. The space is filled with gas called interstellar clouds. When the gas gathers in one place, a center of gravity is created there, and the surrounding gas gathers there. The temperature of the center of gravity rises steadily, and a baby star or primitive star is born there. A primitive star attracts more gas and increases its mass. As a result, gravity increases, causing a primitive star to contract. However, as the temperature in the center rises, it tries to expand. When the force of contraction and the force of expansion are balanced, a primitive star become a star.
Then, a nuclear fusion begins inside of the star, and the star grows little by little. Stars at this stage are called main sequence stars. The sun is a main sequence star. However, a star with a light mass will gradually darken after this, and eventually it will become pitch black. As the temperature of the central part of the main sequence star rises steadily, the main sequence star expands little by little. As the star expands, the outer layers of the star move away from the center, causing it to cool and turn red. Stars at this stage are called red giant stars.
For stars with a mass less than eight times that of the Sun, the outer layers are released from gravity and scattered around. Only the core remains in place. However, for stars with a mass more than eight times that of the Sun, gravitational collapse occurs in the center, causing a supernova explosion. Betelgeuse has more than eight times the mass of the sun. After a supernova explosion. Betelgeuse will become an ultra-dense star called a neutron star. If Betelgeuse had a larger mass, it would become a black hole after a supernova explosion.
If Betelgeuse explodes, it will be brighter than any other star, and the brightness is expected to last for three months. Also, Betelgeuse is located about 600 light-years away from Earth, so the Betelgeuse you can see now is the Betelgeuse from about 600 years ago. If you see the explosion, it means it already exploded about 600 years ago.
Perhaps Betelgeuse has already died. If you see a supernova explosion of Betelgeuse, it’s invaluable because no supernova explosion has ever been observed at close range. It’s very sad that Betelgeuse disappears, but I’d love to see a supernova explosion while I’m alive.