here are the structures i hope it helps
Answer:
primary, secondary, tertiary, and quaternary.
Taxonomy is the classification of things; organisms.
Hope this helps.
A. The conditions under which the organism died and how it was buried.
Reason for Answer: This is because fossils are used to determine the relative age of sedimentary rocks and are used to provide information on past climates, environments, and many more.
Nuclear reactors use hydrogen and they are an up and coming energy source.
There are also hydrogen fuel cells.