A man with a shaved head and a button-up shirt looks into a microscope near a poster about red blood cells .
It is improbable that a man looks through a microscope at a slide of blood in a classroom .
There is a better than even chance that a man looks through a microscope at a slide of blood in a classroom .
It is improbable that a man looks through a microscope at a slide of blood in a classroom .
A man looks through a microscope at a slide of blood in a classroom .