The correct answer is an accumulation of microorganisms in deep marine environments.
Chalk rock refers to a pure form of limestone produced in tropical and warm seas about 100 million years ago in the Cretaceous period. The microscopic marine algae known as coccoliths thrived in the ancient seas. Their shells were comprised of calcite. With the death of the algae, their bodies sunk to the floor of the sea and sediment of chalk got deposited.
Over many years layers of chalk sediment got deposited and resulted in compaction of loose sediment into solid chalk rock.
A mentor is a person who plays the important role of helping another individual to become great person and achieve their potential.
<h3>Who is a mentor?</h3>
A mentor is an individual or person who plays the role of a guide and tutor to another individual in order to help this person to into a great person.
The individual mentored by a mentor is called a mentee.
Mentors are important in the lives of their mentees and to the society at large, as they help build responsible individuals in the society.
A teacher can serve as a mentor to his/her students.
A religious leader can serve as a mentor to their congregants.
Parents can serve as mentors to their children.
Therefore, a mentor is a person who plays the important role of helping another individual to become great person and achieve their potential.
Learn more about mentors at: brainly.com/question/26289842
The answer is D
One way to remember this is when you are building a bridge there is one piece right in the middle that keeps the whole thing from collapsing that is called the key-stone. If a keystone species goes extinct then the rest of the ecosystem will crumble around it.
Answer: Any of a number of organized or specialized structures within a living cell.
Explanation: Hope this helps
For the first question the answer is C. We know this because Dalton considered matter to be composed of very tiny indivisible particles called atoms which means it can't be further subdivided and thus no sub-atomic particles. And for the second question the answer is the Last one: <span>Ernest Rutherford. The rest of them did not give evidence of the existence of a nucleus or gave poor evidence. Hope this helps</span>
