Steve’s Intro Psych instructor collects homework assignments after every class. There are periods when she awards extra credit after every assignment; at other times, five assignments will go by without extra credit. To increase his chances of getting the extra points, Steve consistently turns in the homework. Steve is reinforced on a – schedule.

variable-ratio

Explanation:

answer; /// (a) and (b) ; /// but i believe the correct answer is ; /apart from fines and jail time, driving under the influence puts the life of the driver and everyone else on the road at risk; (b)

the correct answer is modern american cars are not available due to trade restrictions.

trade between cuba and the united states have serious restrictions. the u.s. imposed an economic embargo on cuba, that among other things means that modern american cars are not available due to trade restrictions.

in response to some governmental actions of the authorities from cuba, president john f. kennedy proclaimed an embargo on trade between both countries in february 1962. the trade embargo remains active until this day and was implemented directly by the departments of commerce and the department of treasury.

in president trump’s administration, there is a national security presidential memorandum that "strengthens the policy of the u. s.", affecting trade with cuba.