science

2. loop of flexible material used to link two or more rotating shafts mechanically, most often parallel
5. the action by a celestial body of going round in an orbit or elliptical course
8. to move
10. a unproven statment.
13. he central or innermost portion of the Earth, lying below the mantle and probably consisting of iron and nickel
14. the process of moving
15. a process that makes something work
17. region of the solar system beyond the orbit of Neptune, some 30–1000 astronomical units from the sun, containing up to one thousand million icy planetesimals or comet nucle
19. a fixed luminous point in the night sky which is a large, remote incandescent body like the sun.
20. an imaginary line
21. what in the night sky

1. a continuous area or expanse which is free, available, or unoccupied.
3. measures the distance north or south of the equator
4. a big fire ball that lights up the sky
6. the planet we live in
7. the length of a straight line that extends from one edge of a tumor or other object, through its center and to the opposite edge
9. what pulls us to the floor
11. small, rocky objects that orbit the Sun
12. to go around something
13. frozen leftovers from the formation of the solar system composed of dust, rock, and ices
16. the top of something
18. how something is placed