Geologic Time Scale.Scientists decide when an era begins<span> and </span>ends<span>, due </span>to<span> mass extinction. ...</span>Scientists determine<span> when drastic changes </span>are<span> made by the fossil record, which shows earths past organisms that have become extinct.</span>
Answer:
stack
Explanation:
A stack is a rock in the sea near a coast that is formed by wave erosion.
A= cell wall
B= cytoplasm
C= Plasmid
Because mostly some microorganism may be very small and harmful that can affect humans or animals just by the experience of the microorganism.
