Where are the statements? Can’t see them to answer your question.
I believe the answer is D :)
What is the usual relationship between a country’s standard of living and literacy rate of that country? Usually the relationship between a country's standard of living and literacy rate directly relate to one another. When a country has a high standard of living, the literacy rate is also high because the norms are set to a higher standard. In society, everything relates to one another and because of one thing comes another outcome and so on.
B. They ruled that segregation was legal as long as the 'separate but equal' factor applied :)<span />
Answer:
Research is practical and realistic because it is based on the scientific method, which demands that research should be start with an hypothesis, that should be falsifiable (meaning that it can be proven right or wrong), followed by a scientific study in which the hypothesis is tested.
If the hypothesis is proven to be true, it does not mean that is conclusions will hold true for eternity, they could be proven wrong by further studies.
For this reason, research is both practica, because it is based on a practical method: the scientific method, and realistic, because it has a limited scope, and limited, verifiable understanding of reality, and can be proven wrong with other studies.