The collection of interesting encyclopaedia competitions for primary and secondary school students in 2025 and answer one, natural science category 1. Choices: what is the week of earth's rotation? A. 12-hour b. 24-hour c. 30-day d. 365-day answer: b (the rotation of the earth causes day and night, approximately 23 hours and 56 minutes and 4 seconds, usually close to 24 hours) 2. The diagnosis: rainbow is formed mainly because of reflection and reflection of light. () answer: zoo (reflection, reflection and dissipation of sunlight through raindrops, forming a seven-colour spectrum) 3. Filling questions: the largest planet in the solar system is . Answer: jupiter (which is 2. 5 times the sum of the other seven planets) 4. Select question: why is the water pipes prone to freezing in winter? A. Larger quality after water freezes b. Larger volume after water freezes c. Cold constriction of water pipes d. Answers for over-temperature thinness: b (reduced density when water freezes, about 9 per cent swelling, resulting in rupture of pipes) 5. Lightning and thunder happen at the same time, but when we see lightning, we hear thunder because light spreads faster than sound. () answer: √ (light speeds about 300,000 km/s and sound speeds about 340 m/s) ii. The selection of the human history category 6. A. Duft b. Lee baek c. Wang wai's answer: b. Four of china's ancient inventions were designed for navigation. Answer: a compass (which began to be widely applied by song dynasty) to the question of judgment: the episode is the first general history of my country, written by sema-jin. () answer: xx (author: sima, author: sima guang, guide to governance) 9. Choice: what is the most popular language in the world? A. English b. Spanish c. Chinese d. Answers in arabic: c. (over 1. 4 billion people use chinese as their mother tongue). The festival is dedicated to the memory of our ancient patriot poet. Answer: tsuohara (tru, from the time of the war, the people of the country remember with a dragon canoe and a crotch) iii. The common sense of life category 11. A. Banana b. Apple c. Bread d. The answer to this question: a (bananas containing large quantities of magnesium, empty abdominal consumption may lead to an imbalance in blood)12. The judgment is that when a mosquito bites, soap water can stop itching because the soap is alkaline and acidy in mosquito saliva. () answer: 空 (a mosquito saliva has an antic acid, alkaline soap can be neutral) 13. Filling in: the correct brushing of teeth is (brushing/stamping). Answer: argumentation (breathing better cleans the teeth, cross-brushing damaged teeth) 14. Select question: which of the following acts helps protect the eyesight? A. Read and write mobile phone b. For a long time with an eye 30 cm from the book c. Read and read d. Lie on the screen in a dark light: b (keeping a distance of 3040 cm is the key to protecting the eyesight). Adjudication: sprouted potatoes can eat, just remove them. () answer: xx (breathing potatoes produce ronino, even if there are residuals of chrysanthemum, possibly poisoning) iv. Iii. Technical frontier category 16. Choice: our successful mission in 2024? The answer to question number one, d. The canoe 17, is: b. Filling in blanks: a. I. Is . Answer: ai (artificial inteligence). Adjudication: the 5g network is 10100 times faster than 4g, mainly in the fields of autopilot, telemedicine, etc. () answer: √ (5g peak rate above 10gbps) 19. Select question: what are the following sources of energy? A. Coal b. Oil c. Solar d. Natural gas answer: c. (recycleable solar, wind, hydro etc.) 20. Filling out: the name of our first mars car is . Answer: salvatore (from the god of fire in china's ancient mythology) v. The animal and plant knowledge group 21. Select question: what are the following animals? A. Penguin b. Bat c. Crocodile d. Goldfish answer: b (bats are the only flying mammal who feed their calves with milk) () answer: x (chlorophyll mainly absorbs red and blue light, reflecting green light, so leaves are green) 23. Fill in the question: the plant known as the “activated fossil” is (at least one answer). Answer: silver almonds (or aquariums, guacamole, etc.) (almond almonds already exist in dinosaur times). Male b. Female c. Gender-neutral d. Gender-neutral answer: b. (bee king is a fully developed female, responsible for spawning) 25. Adjudication: the hyena is closed because it is “weak” and it is biological stress. () answer: question six, fun cold knowledge 26: which of the following animals can see more color in their eyes? A. Human b. Dog c. Bee d. Cat answer: c. (bees can see ultraviolet light and sense a colour more than humans) 27. Filling in: the smallest bird in the world is . Answer: hummingbird (the smallest hummingbird is only 5 cm long and weighs about 2 g) the polar bear's skin is actually black, its hair is transparent and it looks white because of the light refraction. () answer: √ (black skin helps absorb heat, transparent hair reflector) 29. Select question: why do onions shed tears? A. Onions release acid gas b. Onions release sulphur-containing compounds to stimulate eye c. Onions with volatile scent d. Onion-cutting action to stimulate tears answer: b (cracking of onion cells produces a tear-gas factor (sulphates of sulphate s oxide), irritating eye tectonic tears) 30. Filling: human hair is about root (filling range). Answer: 100,000 and 150,000 (an average of about 100,000 yellows and 120,000 whites) 31. Select question: what kind of fruit is not growing on trees? A. Apple b. Banana c. Pineapple d. Orange answer: c. Snails are the most teethed animals in the world, and they grow on their tongues. () answer: filling the question: the largest desert in the world is . Answer: the sahara desert (with an area of about 9. 2 million square kilometres) 34. Select question: which of the following insects can “sing”? A. Butterfly b.蝉c. Tungsten d. Ant answer: b. The fireflies glow to court, and the males attract the females by flashing. () answer: 空 (different fireflies have flash frequencies, which are “lights”) 36. Filling in: the strongest part of the body is . Answer: teeth (later than diamonds) 37. Select question: which of the following plants will “eat” insects? A. B. Piggrass c. Hanging d. Cactus answer: b. The moon itself glows, and the light we see is from itself. () answer: x (mount reflecting solar light, not luminous) 39. Fill in: the largest animal in the world is . Answer: blue whales (30 metres older than adults, weighing about 180 tons) 40. Select: why are cooked eggs more likely to be skinned? A. Answers to b. High temperature when protein condensation separates the egg shell from the egg shell, making the egg shell softer by c. Water evaporation, and to d. Egg size swells and breaks the egg shell: a. (boiled egg purified and chromosome, condensed protein condensed and detached from the egg shell) answer: 空 (sun has to be fired from behind, so rainbows appear in the opposite direction of the sun) 42. Fill in the question: one of our “national tree” candidates is (at least one answer). Answer: silver almonds (or pine trees, e. G., not yet officially identified) 43. Select question: which of the following are amphibians? A. Oogway b. Frog c. Crocodile d. Snake answer: b. (frog larvae breathing in water, adult lumber breathing in water) 44. Adjective: lead is the main component of the lead core, which is therefore called the “pent”. () answer: x. Filling in blanks: the cells in human blood that transport oxygen are . Answer: red cells (homoglobin in red cells combined with oxygen) 46. Select question: which of the following is chemical change? A. Water ice b. Rust c. Glass broken d. Alcohol volatilization answer: b (oxy oxide of the new substance, chemically modified)。() answer: x (bats are positioned by ultrasound echoes, with eyes mainly used for sensory light)
