Bird skeletons are very delicate, and therefore, difficult to be preserved. The bones of the birds are soft. The small animals are very prone to physicochemical as well as biological decay. This is why the fossil record of bird is incomplete and well-preserved fossils of birds are rare to find, except at a few unusual sites.
An unknown element is a element that has been discovered not too long ago.Or for say,ARE in fact located on the periodic table.When there is a new one discovered,that will be added to the periodic table as well.
All of them are true to exceptD
R equals 4 3/5
i hope i helped.
Answer:
The biggest shark weakness is going in the state of tonic immobility when they're upside down. Other than that, have fun trying to poke it's eyes, gills or to punch its snout.
Explanation: