what factor explains why the Portuguese did not engage in direct trading relations with West Africa until the fifteenth century

the answer to fill in the blank in this question would be the word resource, it is defined as the money, material or people (since human resource is a very valuable good) that a company or a person has at disposition (meaning they can use the resource as they see fit), to be able to complete a task or achieve a goal.  

no one really purchased it themselves, it was all america, they had debates etc.

a stronger central government  

its what they are

in londan the most because it was one of the growing countries