A doctor may suspect a pleural effusion based on a person's symptoms and physical examination. Doctors may use auscultation (listening with a stethoscope), percussion (tapping on the chest), and other maneuvers when a pleural effusion is suspected. Most often, pleural effusions are discovered on imaging tests.
I am my significant other. there is no other half of us. we are not a whole. having said that, having someone in your life to love and engage with on a level so many cannot experience, and a person who gives you purpose in life is what is often defined as the significant other. you don't find that person, they don't find you..
So the more similar things are to each other, the more likely we are to see them as a whole. The more dissimilar things are to each other, the more likely we are to see them as being separate from each other. Another example of the similarity principle can be found in the example below. Note how the similar colored dots appear to form a line, almost as though they were one unit.