What is the opposite of spend

Explain the pathophysiologic changes that can cause the signs and symptoms associated with common bile duct obstruction.

Rectangle pqrs has vertices p(1, 4), q(6, 4), r(6, 1), and s(1, 1). without graphing, find the new coordinates of the vertices of the rectangle after a reflection over the x-axis and then another reflection over the y-axis.

What is crystallographic data processing and structure determination? what are the physical infrastructures of x-ray crystallographic structural biology? who can tell me detailed information? any would be appreciated. in advance!