The gestation period of the following 20 animals:
1. African Elephant: 640 days
2. Rhinoceros: 560 days
3. Giraffe: 450 days
4. Porpoise: 360 days
5. Horse: 337 days
6. Cow: 280 days
7. Orang-utan: 275 days
8. Human Being: 267 days
9. Reindeer: 246 days
10. Polar bear: 240 days
11. Honey Badger: 180 days
12. Panther: 93 days
13. Cat: 64 days
14. Dog: 64 days
15. Fox: 54 days
16. Kangaroo: 40 days
17. Rabbit: 31 days
18. House Mouse: 19 days
19. Hamster: 16 days
20. Opossum: 13 days
