01. Always singing off-key, or even being unable to sing a very simple song accurately, is called amusia.

02. A survey shows that 62% of boys believe they would rather play with their dogs than with their girlfriends.

03. When television first appeared, the screen was round, but it was later changed to a square shape to accommodate the rectangular field of vision of humans.

04. Sharks are the only known animals that almost never get sick. They have strong immunity to most diseases, including cancer, and can live for 70-100 years, making them long-lived aquarium animals.

05. Roundworms can grow up to 30 centimeters long in the human body. Once they reach this length, they can crawl out of the body through any gap or hole on the surface of the body, including the corner of the eye.

06. Clear nasal discharge is mostly caused by a cold, while greenish nasal discharge is mostly caused by a viral cold.

07. Strictly speaking, urine is much cleaner than saliva, as the number of bacteria in saliva is hundreds of thousands of times that in urine.

08. Eating bitter foods can increase hostility and aggression, meaning that bitterness and aggressive behavior are related.

9. Gray hairs can be plucked, and plucking gray hairs will absolutely not cause more gray hairs to grow.

10. If you can't find the remote control for your wall-mounted air conditioner, you can open the air conditioner cover. There is a small hole on the right side. Just poke it to turn on the air conditioner.

11. In fruit flies, if one of the adjacent cells has a problem, the other will "eat" it to ensure the system can operate stably.

12. Psychological experiments have shown that people are generally more willing to believe what is said in a soft voice.

13. The Chilean sheep-eating tree can lure lambs or other animals with its flowers, then use its sharp thorns to kill them at the foot of the tree, and finally absorb nutrients from the decaying animal carcasses through the soil.

14. A survey shows that only 55.2% of people can accept others entering the toilet while they are using it.

15. The animal with the largest claws known to humankind is the Therizinosaurus, which lived during the Cretaceous period, with claws measuring approximately 75 centimeters in length.

16. A cow doesn't get angry because of red; it can't actually distinguish red from other colors.

17. The fastest growing fingernail is the middle fingernail, and the slowest growing fingernail is the thumbnail. Compared to toenails, toenails grow at only one-quarter the speed of fingernails.

18. The main food of weasels is animals such as rats, locusts, and sparrows. They will only steal chickens when they really can't catch any other prey.

19. Strictly speaking, volleyballs can be kicked with the feet, because the World Volleyball Federation stipulates that any part of the body can come into contact with the volleyball.