The correct answer is letter A.
Labor Union is a stable and permanent association of both urban-industrial, rural and service workers, who come together from the realization and resolution of common problems and needs.
The answer is b african slave merchants
If you mean polio then <span>it dropped by 6000 in 1962 or the first year when the vaccine was released</span>
The increase in trade helped enlarge towns and cities in Europe because it gave the towns and cities an economic base upon which to grow