<span>c.)CBO is the correct answer</span>
Because the slaves are what worked the economy, while everyone else did nothing. Without the slaves the entire thing would collapse because slave owners would not want to work.
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The students in Puerto Rico often reached the schools they are in through walking. So, the answer to the question above is letter A. They do this often as some of the schools are accessible this way. It is also said that walking around towns in Puerto Rico is quite safe.
Answer: adaptation, prevents brain from being overwhelmed by unimportant stimuli
