Science Basics for Kids

1. Popular science knowledge for children

1. Approximately how many tons of water do people drink in their lifetime? (80 tons).

2. A dripping faucet will drip 200 ml of water in 15 minutes. There are nearly 20 liters of water every day. How many tons of water will be wasted in a year? (7 tons) 3. Give some examples of how to generate electricity? (Thermal power generation, hydropower generation, wind power generation) 4. What are the principles of environmental protection law? (Principle of prevention first and combination of prevention and control; polluter-pays principle; environmental rights principle; coordinated development principle; public participation principle; sustainable development principle) 5. Which level of protected animal does the white-headed langur belong to in my country? (Level 1) 6. Please tell us the reasons for the floods in the Yangtze River Basin in 1998. (It is the result of the simultaneous action of "natural disasters" and "man-made disasters".

The direct cause of natural disasters is abnormal climate and excessive rainfall; the causes of man-made disasters mainly include three aspects: first, the destruction of surface vegetation, water and soil The loss is serious. Second, the continuous reduction of rivers and lakes has further reduced the flood storage and discharge capacity. Third, necessary flood control measures cannot keep up, and urban flood control standards are low.) 7. From 1980 to 1995, How much has the world's forest area decreased? (180 million hectares) 8. Water shortage has become a major problem facing my country's urban development. According to statistics, more than 300 cities in my country are currently short of water. How much economic loss is caused by water shortage in my country every year? How much are the economic losses caused by water pollution? (More than 10 billion yuan, more than 40 billion yuan) 9. What percentage of freshwater resources accounts for the earth’s water resources? (3%) 10. What is the proportion of polluted rivers in my country currently? (90%) 11. With the increase in population, water resources have become a global problem. The per capita water supply in the world today has been reduced by 1/3 compared to 25 years ago. How much has the world’s water shortage affected today? country? (80 countries) 12. Mercury, cadmium, chromium, lead, and arsenic are a type of pollutants that are very harmful to the human body and are called the "five poisons". After these pollutants enter the water body with the wastewater, they are absorbed by plankton. Small fish eat plankton, big fish eat small fish, and people eat polluted fish. The pollutants will gradually accumulate in the human body. We call this Why is it related? (Food chain pollution) 13. According to scientists’ observations, the global climate is gradually warming. What is the main cause of climate warming? (Human production activities emit a large amount of carbon dioxide) 14. What if you are missing? Will all living things on earth become extinct, including humans? (Air and water) 15. What harm does carbon monoxide gas do to the human body? (The human body relies on hemoglobin in the blood to carry oxygen to various tissues and organs. After inhaling colorless and odorless carbon monoxide, it will enter the human blood. The ability of carbon monoxide to bind to hemoglobin is 250 times stronger than oxygen. It quickly seizes the blood The position where oxygen combines with hemoglobin in the air, causing hypoxia in the brain and body, which can lead to death in a short time) 16. Smoke and dust are solid particles in the atmosphere with very small diameters, and those smaller than 10 microns can float in the air for a long time, which is called What? What is it called if it is larger than 10 microns and can fall to the ground quickly? (Floating dust, falling dust) 17. In the 1990s, due to serious air pollution, a city in northern my country was covered in smoke and dust, and was lost in satellite photography.

What is the name of this city? (Benxi City) 18. When is the "World Environment Day" every year? (June 5) 19. What is the polluter pays principle? (Whoever pollutes will control it, whoever develops it will protect it) 20. my country’s seven major water systems are all polluted to varying degrees. Please rank them in order of severity of pollution (in order: Liaohe River, Haihe River, Huaihe River, Yellow River, Songhua River, Pearl River, Yangtze River) 21. How much garbage does our country produce every year? (More than 80 million tons) and at what rate is it growing every year? (10%) 22. What are the dangers of garbage? (1. Contaminate soil, groundwater, atmosphere, etc., affecting the urban environment and residents’ living conditions; 2. Occupy valuable land resources.

) 23. In December 1952, the London Smog Incident shocked the world, killing more than 12,000 people within two months. What was the cause of the London Smog Incident? (Exhaust gas pollution caused by coal burning) 24. In Cape Helena in South America, which is the closest to Antarctica, almost all animals there are blind: for example, sheep will get cataracts and become blind. Hunters can easily pick up a blind sheep. The blinded hare went home to enjoy the food. The wild birds flying in the sky strayed into people's homes because of their poor eyesight and could not tell the direction. Even the fish in the river were blind. Many people living here suffered from skin cancer and cataracts. Diseases such as slow plant production and reduced crop yields, please ask.

Why is this? (The ozone layer above this area has been severely damaged, caused by excessive ultraviolet rays from the sun) 25. How high is the ozone layer above the ground? (20-30 kilometers) 26. What is the main reason for the destruction of the ozone layer? (The result of chemical materials used by humans such as Freon evaporating into the air) 27. When is the International Ozone Day every year? (September 16) 28. What disease will have the highest incidence rate caused by excessive UV damage? (Keratitis, cataract) 2.9, What is the population of 1.2 billion? Let's give some vivid explanations: If the Chinese stood hand in hand at the equator of the earth, how many times could they circle the earth? (50 circles); How many thousands of tons of food do people across the country eat in a day? (780,000 tons); how many thousands of tons of meat? (40,000 tons). 30. What kind of pollution exists in modern family rooms? (Human body pollution, building material pollution, home appliance pollution, kitchen pollution, pesticide pollution) 31. When is Arbor Day in my country every year? (March 12) 32. Why are there not as many stars seen in the sky over the city as in the rural sky, and the moon is not so bright? (One is that air pollution over the city blocks the light from the sky; the other is light pollution caused by artificial daylight. After sunset, billboards and neon lights on bustling streets and squares make the city night look like daytime.

These all affect the contrast between light and dark over the city to a certain extent) 33. If there were no forests in the world, how much fewer creatures would there be on land? (90%); How much will the oxygen in the air decrease? (2/3). 34. What are the three categories of light pollution? (Internationally, light pollution is generally divided into three categories: white pollution caused by sunlight reflected on the surface of buildings, artificial daytime pollution caused by nighttime advertising lights, neon lights, and street lights, and colored light pollution produced by various colored light sources in indoor entertainment venues).

2.50 Science Tips

1. Rabbits use their legs to slap the ground to convey information. Most of the rabbits that slap the ground with their hind legs are male rabbits. This is a signal to the female rabbit. A way to express emotions. 2. The largest monkey in the world is the baboon, and the smallest monkey is the tamarin. 3. The real name of the "four different elephants" is elk, which is a rare animal in my country. 4. Why does ice cream steam? ? The reason why the ice cream steams is because there is a lot of invisible water vapor in the outside air. When it comes into contact with very cold ice cream, it will liquefy into mist droplets and surround the ice cream when it gets cold. It looks like the ice cream is "steaming".

5. Why do sunflowers always face the sun? The stems of sunflowers contain a wonderful auxin. This auxin is very photophobic.

When it encounters light, it will go to the backlight side. At the same time, it also causes the cells on the backlight side to multiply rapidly. Therefore, the backlight side grows faster than the side facing the light, making the cells on the backlight side grow faster. Sunflowers are phototropically bent. 6. Why do cicadas shed their skin? The cicada's outer shell (exoskeleton) is hard and cannot expand as the cicada grows. When the cicada grows to a certain stage, the cicada's exoskeleton limits the growth of the cicada. The cicada takes off the original exoskeleton, which is the process of shedding. .

7. How do bees make honey? The bee first vomits the sweet juice of the collected flowers into an empty hive. At night, it sucks the sweet juice into its honey stomach to prepare it, then spits it out, and then swallows it. In this way, it takes 100 times to spit out the sweet juice. ~240 times, finally it becomes sweet honey. 8. Why do stars twinkle? We see stars twinkling, not because of changes in the luminosity of the stars themselves, but because of the obstruction of the atmosphere.

The atmosphere is between us and the stars. When starlight passes through the atmosphere, it will be affected by the density and thickness of the atmosphere. The atmosphere is not absolutely transparent; its transparency varies depending on density.

So when we look at the stars through it on the ground, we will see that the stars seem to be twinkling.

9. Why do people yawn? When we feel tired, our bodies have produced a lot of carbon dioxide.

When there is too much carbon dioxide, oxygen must be added to balance the needs of the body. Because these residual carbon dioxide will affect the functional activities of our body, the body will issue a protective response and yawn.

Yawning is a deep breathing action, which allows us to take in more oxygen and expel carbon dioxide than usual, and also eliminates fatigue. 10. Why can snakes walk without legs? Snakes have many scales on their bodies, which are their outermost layer of armor.

The scales are not only used to protect the body, but also serve as their "feet". When a snake crawls forward, its body forms an S shape.

Each scale on the outside of the S-shape will tilt up to help the snake grasp uneven roads as it moves forward. These scales cooperate with the snake's muscles and can push the body forward, so the snake can move without legs! 11. Why does a person’s hair turn gray as he gets older? There is a substance called "melanin" in our hair. The more melanin, the darker the color of the hair.

If there is less melanin, the hair will turn yellow or white. When humans reach old age, various body functions will gradually decline, and the formation of pigment will become less and less, so the hair will gradually turn white! 12. Why do fireflies glow? Fireflies emit light because they have luminescent devices at the end of their abdomens. The luminescent devices are filled with many phosphorus-containing luminescent substances and luminescent enzymes, allowing fireflies to emit flashes of light.

The purpose of fireflies’ light is not only for lighting, but also for courtship, warning, and trapping. This is also a tool for them to communicate. Different types of fireflies have different lighting methods, lighting frequencies and colors, and they use this to convey different messages.

13. Why does your stomach growl when you are hungry? Your stomach will growl when you are hungry. This is because the food you have eaten is almost finished digesting. Although your stomach is empty, gastric juice will continue to be secreted. At this time, the contraction of the stomach will gradually expand, and the liquid and gas inside will stir up, causing a gurgling sound.

Don’t be embarrassed by your stomach growling next time! Because this is a normal physiological action. 14. Why can’t ostriches fly? A type of giant ostrich bird, but they can't fly into the sky! This is not because their wings don't work, but because their feathers are too soft and their wings are too small, not suitable for flying at all.

In addition, the muscles of the ostrich are underdeveloped and the sternum is flat, which is not helpful for flying. Ostriches live in Africa. Since they have lived in desert areas for a long time, their bodies have gradually evolved into what they are now in order to adapt to the environment.

15. Why does food in cans not go bad easily? Luncheon meat, dace with black bean sauce, and beans in tomato sauce.

These are delicious canned foods that can be stored for a long time without spoiling easily. This is because the can is sealed and bacteria cannot enter.

When people make canned food, they take all the air out of the can and then seal it. In the absence of air, even if there are a few bacteria on the food inside, they cannot survive or reproduce! 16. Why do babies cry non-stop when they are born? Babies cry loudly when they are born. This is not because they are unhappy, but because they are taking their first breath of air! When a baby is born out of its mother's body, the first breath of air they inhale rushes to the throat, which violently impacts the vocal cords, causing them to vibrate and make a cry-like sound.

17. Why does the lizard’s tail still bounce after being broken off? In order to protect themselves, many lizards also use protective colors to hide their appearance. When some lizards are attacked, their tails will break off due to violent muscle contraction. Since some of the nerves in the broken tail are still alive, it will continue to bounce, thus distracting the enemy so that they can escape.

Don’t think that their lives will end like this. In fact, it only takes a few months for their tails to grow back and continue their lives. 18. Why do squirrels have such big tails? Don't look at the squirrel's tail! While the squirrel is jumping up and down the tree, its tail is doing a great job.

It allows the squirrel to balance when jumping on the tree and avoid falling and being injured. In addition, this big tail can also play a protective role in winter, tightly surrounding the squirrel's body, which is both convenient and practical.

19. Why can’t people’s thumbs have one or three sections? The average person has five fingers, and the length of the fingers.

3. Popular science knowledge for primary school students is shorter

1. Primary school students should learn to swim under the guidance of adults; 2. Do not play alone by rivers or ponds; 3. Do not swim in non-swimming areas; 4. Those who cannot swim should not swim into deep water areas, even with a lifebuoy, it is not safe; 5. Make appropriate preparations before swimming to prevent cramps;

2. Self-rescue methods when drowning:

1. Don’t panic, call for help immediately when you find someone around; 2. Relax your whole body, let your body float on the water, raise your head out of the water, and kick the water with your feet , to prevent loss of physical strength and wait for rescue; 3. When the body sinks, press the palms down; 4. If you suddenly cramp in the water and cannot reach the shore, seek help immediately. If there is no one around, you can take a deep breath and dive into the water, straighten the cramped leg, and pull the toes up with your hands to relieve the cramp.

3. Rescue methods when someone is found drowning:

Method 1: Throw lifebuoys, bamboo poles, wooden boards and other objects to the drowning person, and then drag him to the shore; < /p>

Method 2: If there is no rescue equipment, you can enter the water and rescue directly. Approach a drowning victim by turning his hips away from you and then hauling. Hauling is usually done by sidestroke or backstroke.

Special emphasis: If minors find someone drowning, they should not rush into the water to rescue. They should shout for help immediately or use life-saving equipment to call for help.

4. First aid for drowning victims on shore

1. Quickly remove sludge, weeds and secretions from the mouth and nose, keep the respiratory tract open, and pull out the tongue to avoid blockage Respiratory tract; 2. Lift the drowning child so that it lies prone on the rescuer's shoulders, with the abdomen close to the rescuer's shoulders, and the head and feet drooping, so that the water in the respiratory tract can flow out naturally. But do not delay cardiopulmonary resuscitation due to water control; 3. Perform mouth-to-mouth artificial respiration and cardiac arrest; 4. Contact the emergency center as soon as possible or send the drowning child to the hospital.

4. Scientific knowledge about the sun should be suitable for children.

Astronomy definition: Its volume is more than 1.3 million times that of the earth. It is the central object of the solar system and an ordinary star in the Milky Way. The average distance from the earth is 149.6 million kilometers, and the diameter is 1.39 million kilometers. It takes more than 3,500 years to walk from the earth to the sun, and it takes more than 20 years to fly. The average density is 1.409 grams/cubic centimeter, and the mass is 1.989*10^33 grams. , with a surface temperature of 5770°C and a core temperature of 15 million°C. From the inside to the outside are the solar nuclear reaction area, solar troposphere, and solar atmosphere. The central area is constantly undergoing thermonuclear reactions, and the energy generated is emitted into the universe in the form of radiation. One in 2.2 billion of the energy radiates to the earth, becoming the main source of light and heat on the earth. Stars also have their own life history, from birth, growth to aging, and finally death. They have different sizes and colors. , the evolution processes are also different. The connection between stars and life is not only reflected in the light and heat they provide. In fact, the heavy atoms that make up planets and life materials are created during the explosion process that occurs at the end of the life of some stars. .The Sun is an ordinary star that has currently spent about half of its main sequence life on the Herbert-Russell diagram. It is a star with a mass of 198.91 trillion billion tons (about 330,000 times the mass of the Earth). A ball of hot gas (strictly speaking, plasma) with a diameter of 1.392 million km (about 109 times the diameter of the Earth). Its average density is 1.4 times that of water, but this average density implies a wide density range, from ultra-high High-density core to thin outer layer. As a star, the sun's overall appearance properties are: an apparent magnitude of -26.3, a luminosity of 383 trillion watts, an absolute apparent magnitude (Mv) of +4.83, and an absolute hot star The magnitude (Mb) is 4.8. It is a yellow G2 dwarf star with an effective temperature equal to 5770°C Kelvin. The average distance between the sun and the earth orbiting it is 149597870km (499.005 light seconds or 1 astronomical unit). Press Mass meter, its material composition is 71% hydrogen, 26% helium and a small amount of heavy elements. The angular diameter of the sun's disk in the sky is 32 arc minutes, which is very close to the angular diameter of the moon as seen from the earth. It is a A wonderful coincidence (the diameter of the Sun is about 400 times that of the Moon and its distance from us is exactly 400 times the distance between the Earth and the Moon) makes the solar eclipse look particularly spectacular. Because the Sun is much closer to us than other stars, its apparent magnitude Reaching -26.8, it becomes the brightest celestial body seen on Earth. The sun rotates once every 25.4 days (average period; the equator rotates faster than high latitudes), and orbits the center of the Milky Way once every 200 million years. The sun is slightly flattened due to its rotation. shape, which is 0.001% different from a perfect sphere, which is equivalent to a 6km difference between the equatorial radius and the polar radius (the difference is 21km for the Earth, 9km for the Moon, 9000km for Jupiter, and 5500km for Saturn). Although the difference is small, measuring this flatness is This is important because any slightly greater degree of flattening (even 0.005%) will change the influence of the Sun's gravity on Mercury's orbit, making tests of general relativity based on Mercury's perihelion precession untrustworthy. Basic physical parameters of the Sun Radius : 696295 km. Mass: 1.989*10^30 kg Temperature: 5770°C (surface) 15.6 million°C (core) Total radiated power: 3.83*10^26 Joules/second Average density: 1.409 g/cm3 Average distance between the sun and the earth : 150 million kilometers Age: about 5 billion years The solar radiation energy that reaches the upper limit of the Earth's atmosphere is called astronomical solar radiation. When the Earth is at the average distance between the sun and the Earth, the upper limit of the Earth's atmosphere is perpendicular to the unit of solar rays. The total energy of the full spectrum of solar radiation received by an area in unit time is called the solar constant. The common unit of the solar constant is watt/meter2. Due to different observation methods and technologies, the obtained solar constant values ??are different. World Meteorological Organization (World Meteorological Organization) The solar constant value announced by WMO in 1981 is 1368 W/m2. More than 99% of the solar radiation spectrum in the upper boundary of the earth's atmosphere is between wavelengths 0.15~4.0 microns. About 50% of the solar radiation energy is in the visible spectrum region (wavelength 0.0.76 microns), 7% is in the ultraviolet spectrum region (wavelength 0.76 microns), and the maximum energy is at a wavelength of 0.475 microns. Since the wavelength of solar radiation is much smaller than the wavelength of ground and atmospheric radiation (about 3~120 microns), it is usually Solar radiation is called shortwave radiation, and the ground and atmosphere are called

The radiation is long-wave radiation. Changes in solar activity and the distance between the sun and the earth, etc. will cause changes in the solar radiation energy in the upper boundary of the earth's atmosphere. For humans, the glorious sun is undoubtedly the most important celestial body in the universe. The growth of all things depends on the sun. Without the sun, , there would be no life phenomena on the earth, and of course it would not be able to give birth to human beings as intelligent creatures. The sun brings light and warmth to people, it brings the cycle of day, night and seasons, and controls the changes in the temperature and warmth of the earth. , providing various forms of energy for life on earth.

5. Little science knowledge

Why do stars twinkle? We see stars twinkling, not because of changes in the luminosity of the stars themselves, but because of the obstruction of the atmosphere. The atmosphere is between us and the stars. When starlight passes through the atmosphere, it will be affected by the density and thickness of the atmosphere.

The atmosphere is not absolutely transparent, and its transparency will change depending on the density. So when we look at the stars through it on the ground, we will see that the stars seem to be twinkling.

2. Why do people yawn? When we feel tired, our bodies have produced a lot of carbon dioxide.

When there is too much carbon dioxide, oxygen must be added to balance the needs of the body. Because these residual carbon dioxide will affect the functional activities of our body, the body will issue a protective response and yawn.

Yawning is a deep breathing action, which allows us to take in more oxygen and expel carbon dioxide than usual, and also eliminates fatigue. 3.

Why can snakes walk without legs? Snakes have many scales on their bodies, which are their outermost layer of armor. The scales are not only used to protect the body, but also serve as their "feet".

When a snake crawls forward, its body will form an S shape. Each scale on the outside of the S-shape will tilt up to help the snake grasp uneven roads as it moves forward.

These scales cooperate with the snake's muscles and can push the body forward, so the snake can move without legs! 4. Why do sunflowers always bloom toward the sun? The stems under the sunflower discs contain a substance called "auxin."

This substance has the function of accelerating reproduction, but it is optically repulsive. Whenever it encounters light, it will run to the backlight side. So when the sun rises, the sunflower stems immediately hide to the backlight side, and it seems that the entire plant is bent in the direction of the sun.

5. Why does hair turn gray as people age? There is a substance called "melanin" in our hair. The more melanin, the darker the color of the hair.

If there is less melanin, the hair will turn yellow or white. When humans reach old age, various body functions will gradually decline, and the formation of pigment will become less and less, so the hair will gradually turn white! 6.

Why do fireflies glow? Fireflies emit light because they have luminescent devices at the end of their abdomens. The luminescent devices are filled with many phosphorus-containing luminescent substances and luminescent enzymes, allowing fireflies to emit flashes of light. The purpose of fireflies' light is not only for lighting, but also for courtship, warning, and trapping.

This is also a tool for them to communicate. Different types of fireflies have different lighting methods, lighting frequencies and colors, and they use this to convey different messages. 7.

Why does my stomach growl when I am hungry? Your stomach will growl when you are hungry. This is because the food you have eaten is almost finished digesting. Although your stomach is empty, gastric juice will continue to be secreted. At this time, the contraction of the stomach will gradually expand, and the liquid and gas inside will stir up, causing a gurgling sound.

Don’t be embarrassed by your stomach growling next time! Because this is a normal physiological action. 8.

Why can’t ostriches fly? A type of giant ostrich bird, but they can't fly into the sky! This is not because their wings don't work, but because their feathers are too soft and their wings are too small, not suitable for flying at all. In addition, the muscles of the ostrich are underdeveloped and the sternum is flat, which is not helpful for flying.

Ostriches live in Africa. Since they have lived in desert areas for a long time, their bodies have gradually evolved into what they are today in order to adapt to the environment. 9.

Why does food in cans not go bad easily? Luncheon meat, dace with black bean sauce, and beans in tomato sauce.

These are delicious canned foods that can be stored for a long time without spoiling easily. This is because the can is sealed and bacteria cannot enter.

When people make canned food, they take all the air out of the can and then seal it. In the absence of air, even if there are a few bacteria on the food inside, they cannot survive or reproduce! 10.

Why do babies cry non-stop when they are born? Babies cry loudly when they are born. This is not because they are unhappy, but because they are taking their first breath of air! When a baby is born out of its mother's body, the first breath of air they inhale rushes to the throat, which violently impacts the vocal cords, causing them to vibrate and make a cry-like sound. 11.

Why does a lizard still bounce after its tail is broken off? In order to protect themselves, many lizards also use protective colors to hide their appearance. When some lizards are attacked, their tails will break off due to violent muscle contraction. Since some of the nerves in the broken tail are still alive, it will continue to bounce, thus distracting the enemy so that they can escape.

Don’t think that their lives will end like this. In fact, it only takes a few months for their tails to grow back and continue their lives. 12.

Why do squirrels have such big tails? Don't look at the squirrel's tail! While the squirrel is jumping up and down the tree, its tail is doing a great job. It allows the squirrel to balance when jumping in the tree and avoid falling and being injured.

In addition, this big tail can also play a protective role in winter, tightly surrounding the squirrel's body, which is both convenient and practical. 13.

Why can’t people’s thumbs have one or three joints? The average person has five fingers, and the lengths of the fingers vary. However, has anyone noticed that except for the thumb, other fingers also have three joints, but the thumb only has two joints? It turns out that its number of segments matches the other four fingers.

If it has three joints, the thumb will be weak and cannot lift heavier objects; if it has only one joint, it will not be able to cooperate with the other four fingers to grasp things freely! 14. Why don't I feel itchy when I scratch myself? When others scratch ourselves, we feel itchy and laugh constantly; however, when we scratch ourselves, we not only don’t laugh, but also don’t feel itchy.

Based on our mental preparation, the brain will send a message that "there will be no danger", and the nerves will relax accordingly, so we will not laugh or feel itchy! 15. Why is the sea water mostly blue or green? Looking at the sea, we often find that the water is blue or green.

However, when you pick up the seawater, you can only see that it is as transparent and colorless as the water in the past. Original.

6. What is the content of "Encyclopedia of Knowledge" for primary school students

This book introduces a lot of knowledge about animals, military, technology, plants, earth, universe, etc. It is rich and has many related pictures, which is easy to understand.

The encyclopedia knowledge module helps children put down their heavy schoolbags and read about the world in the most relaxed way. Expand your horizons through "Encyclopedia of Knowledge". Here, words of knowledge or stories are narrated, thus shortening the distance between time and space, and connecting yesterday, today and tomorrow into a smooth arc.

Enter the colorful world, decipher the mysteries of science, feel the vicissitudes of history, and enjoy the charm of literature and art.

Extended information: "New Children's Encyclopedia of Knowledge" is a book published in 2008, written by Wang Jindang.

This is a set of children's books that can read, listen, speak, draw, and play. It is a set of children's books that children and parents can read and interact with and can read again and again. Starting from children's reading characteristics and interests, it adopts an open framework, large-scale graphic design, and starts from the life around children to help guide children to accumulate key experiences happily and promote the development of children's brain and thinking.