Without any information i would say the industrial revolution and the pollution that occured because of it
The use of civil service exams
North Korea gets their citizens in fear by showing them propaganda about the United States.
Answer:
The first three criteria are generally considered as requirements for identifying a causal effect: (1) empirical association, (2) temporal priority of the indepen- dent variable, and (3) nonspuriousness. You must establish these three to claim a causal relationship.
Explanation:
answer is explained in this figure
