The US and USSR engaged in proxy wars by

Some of those are very well-known and documented such as Vietnam, Afghanistan, and Angola, but there were also a few lesser-known conflicts in which Soviet and American troops indirectly slugged it out against one another. The Congo, Laos, and Ethiopia saw brutal warfare as these two superpowers fought for supremacy.The answer to this question is that they fought against one another in other conflicts, but never took the war to each other directly.

Explanation:

answer; i believe the two groups were irish immigrants and chinese immigrants;

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.