Some fossils are the O life in shells O casts of shells O minerals in shells

Remember, "skeletons" include bone, the protein shell of crabs or insects, the sturdy ... This mineral makes up the bones and teeth of vertebrates and the shells of ... Some organisms make skeletons of large calcite crystals, as in belemnoids and ... organism were compressed and heated, driving off all the volatiles (H, N, O).

Explanation:

i would say the correct answer is not concrete.

being surrounded by crimes, poverty, and failing schools as well as his own lack of confidence in his abilities.