Minerals do NOT A. have unique crystal structures.
B. have definite chemical compositions.
C. form as the result of natural processes.
D. form as the result of compaction and cementation.

Which statements explains what the fossil records indicates? check all that apply. a) earth is 4.5 billion years old b) many organisms have become extinct c) mammals have always existed on earth d) mass extinctions have occurred several times on earth e) the amount of water on earth has decreased over time?