science and technology
Why don't digital cameras use film?
Why can confidential calls be kept secret?
Why can mobile phones communicate over long distances?
How does the computer touch screen work?
Why can fax machines send pictures and text?
Why don't cordless phones use telephone lines?
What happened to cyber hackers?
What's with the satellite phone?
What is a polygraph?
Why is optical fiber called "nerve" in the information age?
Why can the remote control remote control home appliances?
Why does laser communication have good confidentiality?
What are the functions of digital TV?
Why can color TV display color images?
What is a smart computer like?
What is the use of GPS?
Which radars can detect stealth aircraft?
What material has memory?
Why are genetic weapons so terrible?
How does tear gas make people cry?
What material is the fire suit made of?
Why develop genetically modified organisms?
What diseases can ultrasound diagnose?
How does the air purifier purify the air?
Why is the electronic reconnaissance plane so strange?
Why is there no sound in silent pistol?
Why is the TV tower as high as possible?
What is a "black box"?
How does the hand dryer sense the human body?
What is Bluetooth technology?
What is a PDA?
What is the information superhighway?
What is image communication?
What is quenching?
Why does the electric light come on?
Why can't the exhaust fan be turned on when the gas leaks?
Why does the refrigerator need to protect the power supply?
Why can't wet hands touch the switch and socket?
Why is the sewer pipe of the pool bent?
Why can't the room be cool when you open the refrigerator door?
Why can microwave ovens cook food?
Why are electronic energy-saving lamps particularly energy-saving?
Why does the music doorbell play beautiful music?
Can the electric fan cool down?
Why can a vacuum cleaner vacuum?
Why does the flash for photography turn off as soon as it is turned on?
Why can fuses be insured?
Why do telescopes "see far"?
Why does a knife with water turn blue when baked on a fire?
Why are fireworks colorful?
Why can't we just burn the garbage?
Why do petrochemical plants need torches?
……
culture
Catalogue of animals and plants:
animal
Why do animals hibernate and sleep in summer?
Are all animal blood red?
Why do animals have different tails?
Why do animals have strange tongues?
Do animals dream?
Do animals have rings?
Is a sponge an animal or a plant?
Is coral an animal or a plant?
Can jellyfish predict storms?
If you cut the starfish in half, will it die?
Why do oysters produce pearls?
Why don't sea cucumbers die when they lose their internal organs?
Why do sea cucumbers sleep in summer?
Why do anemones close their tentacles?
Is the sea lily a plant?
Does a shellfish have a brain?
Why do squid need inkjet juice?
Why is octopus an "ocean chameleon"?
Why do crabs spit bubbles?
Why do snails stay where they have climbed?
A little mucus?
Why can earthworms improve soil?
Why do some insects "sing"?
Why do insects shed their skins?
Why do cicadas in trees like to pee?
Why is it itchy and painful to be stung by a caterpillar?
Why do bees die after stinging?
Why do bees dance?
Why don't bees get lost when they travel to collect honey?
Why does the butterfly fly without sound?
Can butterflies move?
Why do dragonflies like to draw water with their tails?
Why do dragonflies always stay at the top of branches or leaves?
Why can leaf worms disguise themselves?
Why do people kowtow?
Why protect ladybugs?
Why does the female mantis eat the male mantis?
Why do small flying insects always fly around under the lights?
Where is the secret of fireflies' luminescence?
Why do locusts move in groups?
How do crickets make sounds?
Why can't cockroaches become extinct?
Why do mosquitoes like to bite people who wear dark clothes?
How many feet does a centipede have?
Is centipede the first of the five poisons?
Why are fleas the jumping champions in the insect world?
Why did the dung beetle roll a dung ball?
Why are ants so powerful?
Why do ants move before it rains?
Why do tailor ants sew leaves?
Why can ants survive for a while without their heads?
How do ants communicate with each other?
Why do flies like to rub their feet everywhere?
Why doesn't the fly fall off when it stops on the ceiling?
Why don't spiders get stuck in cobwebs?
Why do the fish in the river always swim against the current
What's the use of scales on fish?
Why do fish sleep with their eyes open?
Why do fish in the deep sea often shine?
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plant
human body
life
Catalogue of Human Society:
Icaliam
Why is it that making tools is the fundamental difference between people and animals?
Why gathering and hunting was the main way of life of Paleolithic people?
Why is the use of fire a symbol of human civilization?
Why did early humans form primitive people?
Why did early humans form blood families?
Why did early humans form matriarchal clans?
Why did early humans form paternal clans?
Why did early humans form tribal alliances?
Why did primitive agriculture and animal husbandry appear?
Why did primitive religion appear?
Why do "Wushan people" not belong to African immigrants?
Why is Yuanmou man in the childhood stage of human evolution?
Why are "Beijingers" seldom over 30?
Why is the matriarchal clan commune the beginning of national civilization?
Why is the patriarchal clan system the beginning of class differentiation?
Why is Longshan culture the eve of entering slave society?
Why is it called the Paleolithic Age before the appearance of primitive agriculture and animal husbandry?
Why is the appearance of primitive agriculture and animal husbandry called Neolithic Age?
Why were stone tools not eliminated in the early bronze age?
Why did the Iron Age accelerate the collapse of slave society?
Why does the legendary Huang San refer to different things?
Why do the legendary five emperors have their own meanings?
……
Ancient China
Modern China
contemporary China
history of the world
Catalogue of astronomy, geography and transportation:
astronomy
Why do you want to study astronomy?
Why is it difficult to see the face in the center of the galaxy?
What is the Milky Way?
Why is there a gap in the middle of the galaxy?
Why is the Milky Way a "flowing river"?
How many stars can the Milky Way be born in a year?
How did the universe come into being?
Which planet is the largest in the solar system?
Is the universe expanding?
What are the "three holes" in the universe?
What is the age of the universe?
Why can "quality" determine the fate of the universe?
Does the universe have an end?
Why do you say that most substances in the universe?
Is invisible?
What is the cosmic calendar?
Why in the universe
Most of our planets are round?
How was the solar system formed?
Why does the sun shine and heat?
Is the solar system in the center of the galaxy?
Why does the sun rotate slower than other stars?
Why is the position of the sun different in winter and summer?
Will Sun Die?
Why is there only life on earth in the solar system?
Why does the sun come out at five or six in the morning?
How high is the temperature of the sun?
What is the solar wind?
What is the solar wind made of?
Where does the great energy of the sun come from?
What is a sunspot?
What is a solar flare?
Why are sunspots and flares not the "patent" of the sun?
Is there a solar system outside the solar system?
Why was the solar system discovered by Copernicus?
Why is the density of the sun so small?
Why is Sun An an ordinary star?
Why the more sunspots, the brighter the sun?
Why is it important to study white light flares?
Why does the sun never set in the Arctic in summer?
Why can sunshine keep people warm?
Why is the earth an oval sphere?
What is the ecological evolution process of the earth?
Does the earth have another brother?
Why do you say that the water on earth comes from outer space?
Will the earth be attacked by asteroids?
Why does the earth turn?
Why can't you feel the earth turning?
Why study the space between the sun and the earth?
How was the moon born?
Why is there no atmosphere on the moon?
Why does the moon have a phase change?
Is there Chang 'e on the moon?
Why does the moon always follow people?
Why is the lunar shell "surprisingly thick"?
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geography
traffic