The population of Puerto Rico traces its ancestry in mostly the Spanish colonists and the indigenous people of the island. They have mixed over time and gradually created a mestizo population, which became the dominant population on the island and still is. There are of course some other influences in the gene pool of the Puerto Ricans, with some of it being from the African continent because of the African slaves that were brought, but it is a small minority, and it is also a population that has been heavily mixed.
Free trade agreements
The goal of both NAFTA and the EU is to create free trade between the countries of their given continent.
Free trade means no tariffs on imported goods and the ability of corporations to move their products from country to country with no penalty. For NAFTA, Canada, the US, and Mexico can freely trade across the borders and tariffs will not be imposed under the treaty.
The hands of the people
Assuming you mean direct democracy.
It depends what it interacts with but it makes bubbles for a chemical or physical change happening to it