Curtis works hard at school because he knows it will lead to good grades, praise from his mother, and money from his father. it is clear that are effective with curtis.

Secondary reinforcers

Explanation:

A secondary reinforcer is a type of stimulus or situation that functions as a reinforcer because it has been paired with another stimulus that also functions as a reinforcer. In this case, the reinforcer is the good grade. In turn, the secondary reinforcers are the praise and the money, both of which seem to be effective with Curtis.

answer; the parasympathetic nervous system;

answer; silence;