Answer: Minerals
Explanation: The body decomposes and after about 40 to 50 years bones are mostly brittle and dry with no traces of flesh. After thousands of years bones also disintegrate (decay) leaving brittle mineral frame. The life of bones is determined by the soil type its buried in, nuetral soils takes longer then acidic soil condition.
In this case osteocytes(bone cells) are the first to decompose followed by the cartilage and bone marrow, leaving behind mineral traces that scientist can study after thousand years.
Water and ice and i dont know the rest
It depends on which virus you are referring to specifically. Viruses come in many shapes and types; their variations are tremendous.
For HIV and Influenza, viruses acquire their envelops after maturation, during the budding off or detachment stage from the host cell.
Hope this helps! :)
Covalent bond because a covalent bond is when it only shares electrons and it doesn't give or lose.