Who explained how gravity is universal in nature

Issac Newton

Explanation:

After the "Apple hit him in the head" he studied and explored the idea, and realized gravity is universal, with any object with mass.

Hope this helped.

LunarRose3

the spanish  

hope this meaning spain btw

answer is b.

  it is always the best policy to have good communication and good relations between individuals and, specially, between leaders of the countries. for this purpose, among others, there is a common place, the united nations, where the representants can present his and learn about the other country's policies.