When secondary sex characteristics appear before the age of 8 in girls and 9 in boys, it is called

Perry works at a job where he is paid by commission. For every car Perry sells, he gets 10 percent of the profits. Perry is being reinforced on a ________

a. fixed-ratio schedule b. fixed-interval schedule c. variable-interval schedule d. variable-ratio schedule

__________ is a personality trait that describes how anxious and vulnerable to negative emotions a person is

Fill in the blank(s) with the appropriate word(s).