Selective serotonin reuptake inhibitor. Selective serotonin reuptake inhibitors (SSRIs), also known as serotonin-specific reuptake inhibitors or serotonergic antidepressants,[1] are a class of drugs that are typically used as antidepressants in the treatment of major depressive disorder and anxiety disorders.
Then you're looking for the midpoint! The midpoint of a line segment is the point located midway between the endpoints of the line segment. This tutorial tells you about the midpoint of a line segment.
Midsegment Theorem Proof. The mid segment theorem states that a segment that connects the mid points of any two sides is parallel to the third side and also its measure is half the measure of the third side. That is, DE ll AB and DE = $\frac{1}{2}$ AB. Therefore, CA = CD + DA = 2 CD.