Answer:
Migration boosts the working-age population. Migrants arrive with skills and contribute to human capital development of receiving countries. Migrants also contribute to technological progress. Understanding these impacts is important if our societies are to usefully debate the role of migration
Is rounded and found with running water
By rename do you mean turn into an improper fraction?
if so, it is because without turning it into an improper fraction, you cannot subtract 3/4 from 1/4 because you would get a negative answer and that would be incorrect