The correct answer would be: The up-and-down motion of the tongue when sucking.
I hope that helped! c:
<span>The skull protects the brain and the vertebrae protects the spinal cord. The brain and spinal cord are wrapped in three layers of connective tissue called meninges. Between the meninges and the central nervous system tissue is a space filled withcerebrospinal fluid.</span>
<span>The scientist who melted glass to simulate a microscope was Robert Hooke, in 1660. He was an English physicist, and he looked at insects and handheld objects. He named the cell for the cell of a monk, because to him it appeared to be a self-contained room.</span>
The answer is the endocrine system.
The brainest answer would be apprenticed.
