Life knowledge popular science competition short answer questions

Answer 1

The following are some of the short answer questions and examples of their answers:

** 1. Physical Phenomena **
1. When he looked at the bottom of the pool, he felt that the water was not deep. After entering the water, he realized that this was not the case. Why?
- Answer: When light enters another medium diagonally, it will be refracted. When people look at the bottom of the pool from the air, they actually see a virtual image of the bottom of the pool. The position of the virtual image is shallower than the actual bottom of the pool.
2. Usually, the surface of leather shoes had many pores and was not very smooth. When there was dust attached to the surface, the leather shoes would lose their luster. After applying shoe polish and carefully wiping them with a cloth, the leather shoes would become bright and beautiful. Why was this?
- Answer: When the surface of the leather shoes is not smooth and dusty, the light will be reflected when it hits the shoe, and the leather shoes will lose their luster. After applying the shoe polish, the tiny particles of the shoe polish would fill the pores, and the shoe polish would be carefully wiped with a cloth to make the shoe polish spread evenly. The shoe's upper would become smooth, and the light would reflect from the mirror after shining on the shoe's upper, making the leather shoes brighter and more beautiful.
3. When pouring half a cup of boiling water into the glass, the top half of the cup was blurred. Please explain it with junior high school physics knowledge.
- Answer: When half a cup of boiling water is poured into a glass, the boiling water will evaporate and produce water vapor. When the high-temperature water vapor met the lower temperature glass wall, it liquefied into small water droplets and attached to the glass wall, causing the top half of the cup to be blurred.

** 2. Health and Life Knowledge **
1. How to deal with the emergency after the doll was knocked?
- Answer: Immediately apply pressure with your palm for five minutes to reduce the bleeding under the skin. Then, apply an ice pack or a cold compress with a fever-reducing paste. After 24 hours, apply warm water again.
2. Are mosquito repellent buttons and mosquito repellent bracelets useful?
- Answer: The mosquito repellent wristband has a small range of radiation, and the area it covers is very limited unless it covers the whole body.
3. Can a doll shave her head to increase her hair volume?
- Answer: The effect of shaving on hair is limited to stimulating the speed of hair growth. It won't increase hair volume or improve hair quality. The same went for shaving eyebrows and cutting eyelashes.
4. Can the nose of a doll become taller?
- Answer: The height of the nose bridge is mainly affected by the genetic factors of the parents. It can't become taller by pinching it, and it may cause harm to the child.
5. Should he drink vinegar after a fishbone got stuck in his throat? Please state your reasons.
- The answer was no. Vinegar not only could not eliminate fishbones, but it could also cause erosion of the mucus membrane and edema of the esophagus. It was even more dangerous to try to remove the foreign object by swallowing it forcefully or eating it in large mouthfuls. It might cause the fishbone to pierce deeper or even pierce the esophagus.

** 3. Swimming Safety **
1. Summer was a period of high drowning. How could one swim to ensure their own safety?
- Answer: (1) Do not go into the water too hungry or too full. You can only go into the water one hour after meals to avoid cramps.(2) Test the water temperature before going into the water. If the water is too cold, don't go into the water.(3) If you swim in a river, lake, or sea, you must have a companion. You can't swim alone.(4) Observe the environment of the swimming place before entering the water. If there is a danger warning, you can't swim here.(5) Don't swim in the canyon where the geographical environment is unclear. The water in these places is different in depth and cold. There may be obstacles in the water that can hurt people. It is very unsafe. Before diving, make sure that the water depth is at least 3 meters, and there are no weeds, rocks or other obstacles underwater. It is safer to enter the water with your feet first; 7. When swimming in the sea, swim parallel to the coastline. Those who are not good at swimming or have insufficient physical strength should not go deep. Make a mark on the coast and pay attention to whether they are washed too far away. adjust the direction in time to ensure safety.

** 4. Value related **
1. The main content of the core values of the country? What were the four levels involved?
- Answer: The 18th National Congress of the Party proposed to advocate prosperity, democracy, civilization, harmony, freedom, equality, justice, and the rule of law. It also advocated patriotism, dedication, integrity, and friendliness, and actively cultivated and practiced the core values of the country. Among them, prosperity, democratism, civilization, and harmony were the value goals at the national level. Freedom, equality, justice, and the rule of law were the value orientation at the social level. Patriotic, dedicated, honest, and friendly were the value criteria at the individual level of citizens.

** 5. Insect Knowledge **
1. Do all mosquitoes suck blood? Please state your reasons.
- Answer: Not all mosquitoes suck blood. The male mosquitoes 'mandibles had degenerated, and their lower jaws were short and thin. They could not sting human skin, so the male mosquitoes could not suck blood. Female mosquitoes suck blood mainly to reproduce, and their eggs can only mature after they suck blood.

** 6. About volunteer services **
1. What is the spirit of volunteer service?
- Answer: The spirit of volunteer service can be summarized as dedication, fraternity, mutual assistance, and progress. It advocates a spirit of mutual help and no return, that is,"helping each other, helping others to help themselves, selfless dedication, no return." The volunteers use their hands, brains, knowledge, and love to carry out various volunteer service activities to help those in difficulties and crises for free.

** VII. Food Safety in Summer **
1. How is it safer to "eat" food in summer?
- Answer: Fresh: Eat the food you buy as soon as possible. Don't store it for a long time. Try not to leave any food behind. All raw materials and seasoning of fresh food should be eaten within the shelf life;(2) Cleaning: The food should be thoroughly washed before eating, and the food storage place, utensils and containers should be kept clean. At the same time, the raw and cooked food should be stored separately;(3) Cold storage: The temperature of food conditioning and preservation should be controlled below 7 ° C. It is best to wrap it with plastic wrap during cold storage to prevent cross-contamination of food in the refrigerator;(4) Heat: Food should be steamed and cooked before eating, especially seafood such as clams, snails, turtles, bullfrogs, etc.; Personnel hygiene: wash hands thoroughly before conditioning food. If there is a wound on the hand, it should be completely bandaged before conditioning food (the wound should not be in direct contact with food); Eat cold drinks, don't be greedy: eating too much cold drinks will dilute gastric juice, causing disorder of normal flora in the stomach, reducing local resistance and prone to diarrhea.