A black man in a dress shirt is looking through a microscope , while a poster about blood cells is on the wall in the background .
It is probable that a scientist is observing results through a microscope in his office .
It is probable that a scientist is observing results through a microscope in his office .
We doubt that a scientist is observing results through a microscope in his office .
A scientist is observing results through a microscope in his office .