X is mathematically an unknown.
Answer:
central nervous system
Explanation:
because it is under control of our brain
Answer: Glycogen
Explanation: Glycogen is a polysaccharide of glucose. It serves as a form of energy storage in fungi as well as animals and is the main storage form of glucose in the human body. In humans, glycogen is made and stored primarily in the cells of the liver and the muscles.
The landscape in which limestone is eroded to form deep valleys and cavers are called Karst landscape or karst topography. This kind of development start occuring whenever the acidic water starts breaking down the bedrocks near the cracks. As the bedrock starts breaking down slowly, the cracks start to open up creating bigger holes. with passage of time the holes will become big enough to create an underground drainage system for the surface water to flow and form underneath. If the water is unable to flow out and becomes stagnant, then the Karst will start getting bigger.