<em>Answer:</em>
<em>variable-interval </em>
<em>Explanation:</em>
<em>In psychology,</em><em> a variable-interval schedule is described as a schedule of reinforcement which is considered as one of the parts in the operant conditioning and was discovered by </em><em>B. F. Skinner. </em><em>It is also denoted as VI, and is defined as a process whereby "reinforcement" is being given to a specific response only after a well-defined amount of time has been passed i.e, unpredictable time and therefore the amount of time is supposed to be on a variable or changing schedule.</em>
<em>As per the question, studying for professor Wallace's surprise quizzes will be reinforced on a variable-interval schedule.</em>
A U.S.-British airlift of supplies to West Berlin's many citizens and Soviet Union lifting its 11-month blockade against West Berlin.
Most of the time the treat them with some respect just depends on the people