What happens when the diaphragm contracts?
a. the rib cage moves down.
b. the volume of the thoracic cavity increases.
c. the diaphragm rises.
d. the volume of the thoracic cavity decreases.

Wind energy is plentiful in regions with vast open spaces it is a non polluting renewable resource what could be an economic factor that makes the use of this resource less feasible then non renewable resource even in such regions

How does natural selection change thephenotypes within a population over time?

This is a situation in which genes are attached to an organism's sex chromosomes; the sex of an organism influences the expression of a gene.