1. Why do you see lightning first and then hear thunder? Light travels faster in air than the speed of sound.

2. Who was the first Olympic champion in China? (Xu Haifeng)

3. What is the plant representing peace? (olive branch)

4. What was the earliest crop? (wheat)

5. Who invented the steam engine? (Watts)

6. What does the moon revolve around? (Earth)

7. What are the three plains in China? (Northeast Plain, North China Plain, Middle and Lower Yangtze Plain)

8. How many earthquakes occur on the earth every year? (about 5 million times)

9. What is the smallest and coldest star? Brutto

10. What is the thickness of the earth? (atmosphere)

1 1. Why is there a black box on the plane? It is used to record all kinds of situations on the plane when the accident happened and help people understand the cause of the accident.

12. What are the customs during the Spring Festival? Sweep the house, set off fireworks, put up Spring Festival couplets, eat New Year's Eve, etc. )

13. What animals can predict earthquakes? Cattle, horses, donkeys, rabbits, chickens, dogs, snakes, rats, cats, swallows, eagles, etc. )

14. What plants bloom first and then grow leaves? Forsythia suspense, winter jasmine, wintersweet, peach tree, pear tree, etc. )

15. How do bees make hives? Every worker bee has a wax gland at the waist, which can secrete wax. This wax becomes soft and tough after chewing in the mouth, and it can be used to build honeycombs.

16. Why are plastic medicine bottles so light? Because light color can reflect light, dark color absorbs more light in the sun, and drugs are easy to deteriorate. )

17. Why can't I turn off the lights and watch TV? The screen and image of TV set are relatively small. In the dark, vision should be highly concentrated and expanded, and it is particularly sensitive to the light on the screen, which will stimulate the eyes and reduce vision. )

Who invented the airplane? Wright brothers ltd

19. What is the blood of the earth? (magma)

20. What is the skeleton of the earth? (rock)

2 1. Why don't you watch the welding sparks? (contains ultraviolet rays harmful to eyes)

22. What are the ancestors of birds? (Archaeopteryx)

23. Who are the top ten marshals in People's Republic of China (PRC)? (Zhu De, Peng, He Long, Chen Yi, Liu Bocheng, Luo Ronghuan, Xu, Nie, Lin Biao, Ye Jianying)

24. What are the four major oil crops in China? (Rape, soybean, peanut, sesame)

25. What is the insect with the shortest life span? (Mayfly)

26. What is a meteor? (refers to the light trace produced when very small solids or dust in space break into the earth's atmosphere)

27. Who is the most outstanding astronomer in the history of China? (Rolling)

28. Who is the inventor of the battery? (Volts)

29. Where is Mount Vesuvius? (Italy)

30. Who were the first two astronauts to reach the moon? (Armstrong and Aldrin)

3 1. Which province and city is Mount Tai in? (Taian City, Shandong Province)

32. Where is the Amazon River? (Brazil)

33. Where is the Irrawaddy River? Myanmar)

34. What is the tallest mammal? (Giraffe)

35. What was the name of the ancestor of the fish? (amphioxus)

36. What is the name of the most poisonous spider in the world? The wolf found it

37. Who invented the earliest mines? (Patriotic Qi Jiguang)

38. Where does chocolate come from? (made from seeds in the fruit of the cocoa tree)

39. What kinds of calligraphy are there? (cursive script, seal script, official script, running script, regular script)

40. How many muscles does a person have? (639 muscles in total)

4 1. Why does wood float on the water? (Because the density of wood is less than that of water)

42. What is the capital of France? (Paris)

43. What is the capital of Britain? (London)

44. What is the capital of Japan? (Tokyo)

45. What is the capital of Italy? Rome)

46. What is the capital of the United States? (Washington)

47. What are the ancestors of birds? (Archaeopteryx)

48. What are the products of China's four seas? (Large yellow croaker, small yellow croaker, hairtail, squid)

49. What is the largest mammal? (blue whale)

50. What is the largest amphibian? (giant salamander)

5 1. What is the book read by hand? (Braille)

52. Why don't rabbits drink much water? Because there is a lot of water in the rabbit's staple food, it is enough for the body. If there is more water in the intestine, you will suffer from gastroenteritis. But rabbits can drink water when they are short of water.