The Precambrian covers the majority of earth's history.
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About 23 islands or more lack an adequate standard of living.
Answer:
The migration during the 20th century has been mostly from less-developed (poor) countries to more-developed countries.
Explanation:
A is correct because during the 20th century, with the migration policies being made much more friendly and open, the people from the less-developed countries where the living conditions were terrible, to the more-developed countries where they could have much better lives.
B is not correct because it is actually the opposite, where people from different religious beliefs than those of the people of the county of their choice, have migrated and made much more diverse societies.
C is not correct because such migration has not been recorded so far.
D is not correct because the people from more-developed countries usually only visit the less-developed countries as tourists, but very very rarely migrate to them as they are aware of the risks and bad living conditions.
