To cause extinction of a previously classically conditioned behavior what must happen?
a) the CS must occur repeatedly without the UCS.
b) the UCS must occur before the CS.
c) the CR must be repeatedly punished.
d) the CR must occur by itself.

Which statement best represents an economic weakness of the national government under the articles of confederation? a. the national government was unable to collect taxes. b. national and state taxes combined were too high for most services to pay. c. congress set different tax rates for each state, leading to conflict. d. state refused to collect taxes on behalf of the national government