If food is presented to a pigeon every time the pigeon pecks a key, then the pigeon's behavior is on a schedule of reinforcement.

"choosing is refusing" means individuals face an opportunity cost with each decision they make. economists state that every decision involves trade-offs. opportunity cost is the least desirable alternative given up as a result of a decision.

q1: artillery

q2: simon bolivar

q3:   their workers and farmers demanded a return to spanish rule.

q4: drafted new constitutions

q5: oligarchies have replaced monarchies

answer; u.s senate;

answer; technology;