Eutrophication is caused by .

on december 1, 1774, the continental association was created to boycott all contact with british goods. by reversing the economic sanctions placed on the colonists, the delegates hoped britain would repeal its intolerable acts.

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."

answer; automatic fire suppression system;