1. gravity
2. sea animals
3. animals
4. stars conste
5. Planet Earth
5.1. Humans
5.1.1. Female
5.1.2. Male
5.2. Nature
5.2.1. Trees
5.2.1.1. Bananas
5.2.1.1.1. Green Bananas
5.2.1.1.2. Yellow Bananas
5.2.1.2. Oak Tree
5.2.2. Grass
5.2.3. Flowers
5.3. animals
5.3.1. Wolf
5.3.2. Dog
5.3.2.1. Jack Russel Terrier
5.3.2.2. Bull Dog
5.3.2.3. Pitbull
5.3.2.4. German Shepard
5.3.2.5. Golden Retriever
5.3.3. Cat
5.3.4. Rabbit
5.3.4.1. Bunny
5.4. water
5.4.1. Rivers
5.4.2. Lakes
5.4.3. Oceans
5.5. sea creatures
6. Nature
7. space explortion
7.1. NASA
7.1.1. Apollo missons
7.1.2. sarturnV
7.1.3. mercury missons
7.1.4. ISS
7.1.5. Voyager 1
7.1.6. Voyager 2
7.2. NSAU (Ukrainian)
7.3. Roscosmos (Russian)
7.3.1. sputnik
7.3.2. slauit
7.3.3. spelling is proably wrong
7.3.4. souze
7.3.5. ISS
7.3.6. Mir
7.4. ESA (European)
7.4.1. atlas rockets
7.4.2. voyager
7.4.3. ISS
8. planets
8.1. dwarf planets
8.1.1. pluto
8.1.2. Large Asteroids
8.1.2.1. Eris
8.1.2.2. Ceries
8.2. stars
8.3. sun
8.4. comets
8.4.1. Halley's Comet
8.5. milkyway
8.6. meteors
8.7. astronomy
9. rivers
10. living things
10.1. Sea,lake,river
10.2. Plants
10.2.1. power
11. animals
11.1. Land
11.1.1. ocean
11.1.1.1. humans
11.1.1.1.1. Female
11.1.1.2. animals
11.1.1.2.1. Dog
11.1.1.3. plants
12. water
12.1. cars
12.1.1. grass
13. air
14. plants
15. trees
16. people
16.1. Society
17. water
18. climents
19. Rock
19.1. Sediment
19.1.1. Sand
19.2. Igneous
19.2.1. Volcanoes