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 that represents 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 are there on the earth every year? (about 5 million times)

9. What is the smallest and coldest star? (Pluto)

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 during the accident and help people understand the cause of the accident.

12. What are the customs during the Spring Festival? (Sweeping the house, setting off fireworks, posting Spring Festival couplets, eating New Year's Eve, etc.)

13. What animal 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 suspensa, Winter jasmine, Chimonanthus praecox, 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 a beehive.

16. Why are plastic medicine bottles light? (Because light colors can reflect light, dark colors absorb more light when exposed to sunlight, and drugs are easy to deteriorate.)

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

18. Who invented the plane? (Wright brothers)

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 welding sparks? (contains an ultraviolet ray harmful to the eyes)

22. What is the ancestor of birds? (Archaeopteryx)

23. Who are the top ten marshals of the Chinese people? (Zhu De, Peng Dehuai, He Long, Chen Yi, Liu Bocheng, Luo Ronghuan, Xu Xiangqian, Nie Rongzhen Lin Biao, Ye Jianying)

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

25. What is the shortest-lived insect? (Mayfly)

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

27. Who is the outstanding astronomer in the history of China? (Zhang Heng)

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 fish? (amphioxus)

36. What is the name of the most poisonous spider in the world? (Wolf Finds)

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? (One * * * has 639 muscles)

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 is the ancestor of birds? (Archaeopteryx)

48. What are the four major marine products in China? (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 text of the book read by hand? (Braille)

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