1. What's the fastest bird? Swift.

2. How many volts is the safe voltage of the human body? 36 volts, 3. What is the biggest bird in the world at present? Ostrich.

Are sharks freshwater fish? number

5. What does dandelion rely on to spread seeds? Rely on the wind

6. What is the point of supporting the lever? fulcrum

7. Which chromosome determines human sex? Y chromosome.

8. What is the development of chicken? yolk

9. What is the revolution direction of the earth? From west to east.

10. dragonfly water is actually in? Lay eggs.

1 1. What is the state of the eyes when the fish sleeps? Sleep with your eyes open.

12. What is the earthworm's food? Mud.

13. The greater the wind speed, what will the wind do? The stronger.

14. What electricity does the glass rod rubbed by silk bring? Positive electricity.

15. What kind of environment is earthworm suitable for living? Dark and humid.

16. What is the buzzing sound made by mosquitoes? Wings flutter.

17. which country launched the first artificial satellite in the world? The former Soviet Union.

18. there are three ways of heat transfer, conduction, convection and? Radiation.

19. Who invented the electric light? (Edison)

20. Who invented the first shelf? A plane? (Wright brothers) 3. Who invented the car? (Mercedes).

2 1. Is the compass a compass? (yes).

22. Who invented explosives? (Nobel).

23. Who invented papermaking? (Cai Lun).