Answer:
Conditioned stimulus
Explanation:
In the classical conditioned, these terms such as condition stimulus, UCS, CS, NS, etc are being used to modify the behavior of a person, animal, etc. The conditioned stimulus is neutral before as a conditioned stimulus. Ivan Pavlov was the first psychologist who has been used classical conditioning in which a person used CS, UCS, UCR, and CR.
Thus here in the above statement, the person eats a hamburger. Before used it, it was a neutral stimulus but after using it, it becomes a conditioned stimulus.
Okay so I'm not sure exactly if this is talking about primary or secondary sources, but if it is then I'm fairly certain that this would be a secondary source since the student wasn't there to witness it, they're relying on their research to give them information.
Physical maps use color most dramatically to show changes in elevation. A palette of greens often displays elevations. Dark green usually represents low-lying land, with lighter shades of green used for higher elevations. In the next higher elevations, physical maps often use a palette of light brown to dark brown
A. They collect evidence and interpret what it means