Due to the effects of drugs causing behavioural abnormalities, many scientists suggest a theory that "substance may due to operant conditioning." Substance abuse has been one of the hot topics in our society nowadays. For example is the use of cannabis, which is known to be an effective treatment for several ailments, are abused by other people which could mentally impair them.
The answer is C, Europe , you know ... ( Christopher Columbus )
America , also known as the new world.
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You should pick C) Europe because this is what we learn in school so this is what your teacher wants you to pick.
But if you want to get technical ,
The correct answer is D)South Africa , this can be proven<span />
Because then there's no competitions for offices
I'm pretty sure it's C, it makes the most sense.