This is usually called a placebo. They are used as control tests to make sure that a product actually works. A placebo, however, is not merely restricted to pills, though.
 
        
             
        
        
        
Answer: The removal of rock particles by wind, water, ice, or gravity. Works with weathering to continuously wear down and carry away rocks at Earth's surface.
 
        
                    
             
        
        
        
Arteries are blood carrying vessels which have thick, elastic,  muscular walls, have no valves and in which blood flows under high pressure. The make up of arteries is unique to their function of transporting blood under high pressure.  
All arteries carry oxygenated blood from the  heart to all other parts of the body, with the exception of the pulmonary artery which carries de-oxygenated blood from the heart to the lungs. It is the only artery that transports blood which has not been oxygenated.
 
        
             
        
        
        
Answer:
The correct answer is vasogenic edema. 
Explanation:
A kind of cerebral edema in which the blood-brain barrier is disrupted is termed as vasogenic cerebral edema. It refers to extracellular edema that primarily influences the white matter through leakage of fluid from the capillaries.  
It is primarily witnessed surrounding the brain tumors, that is, both primary and secondary and the cerebral abscesses, however, some of the vasogenic edema may be witnessed around the developing cerebral hemorrhage and cerebral contusion.