Mark can answer the physics problem because of patterns of knowledge stored in his long-term memory, which he did not intentionally try to learn. this situation involves mark using what?

Implicit memory  

Explanation:  

Implicit memory: The term implicit memory is a part of the long-term memory that can not be consciously recalled. Through implicit memory an individual can perform skills, habits, or automatic behaviors, for example, driving a car. Implicit memory allows an individual to react in certain ways for which he or she is not consciously aware of the reason for the behavior.

The Implicit memory is also referred to as automatic memory or unconscious memory. It allows a person to utilize past experiences to think about something without being consciously aware.

In the question above, Mark is using implicit memory.

swahili is an extremely rich and complex civilization, a set of ethnic groups articulated by a language and a series of cultural elements that fuse the african traditions, islam and indian culture. this growth was largely a result of the indian ocean trading network that brought in not just man-made riches, but also religious ideas, specifically islam, which had a significant impact on the local culture. furthermore, the development of the swahili language gave a common cultural unity to the people.

d. i assume the underlined word is "role." reformat if it isn't.

explanation:

role is closest to part because when replacing words, "playing a vital decision," "playing a vital activity," and "playing a vital dollar" don't make logical sense. the only meaningful choice is "playing a vital part."

this fits one of merriam-webster's definitions of role: "a function or part performed especially in a particular operation or process."