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.
The hormone that stimulates ovaries to release one egg per ovarian cycle is called follicle-stimulating hormone (FSH). This hormone is produced in the pituitary gland. Most woman will reach puberty by their teen years.
They both include the same acid
D.
Theories always change. That's why science always changes
An atmosphere is a layer of gas or layers of gases that envelope a planet, and is held in place by the gravity of the planetary body.
