Why did the united states enter world war 1 in 1917?

3 reasons

Explanation:

1. The attack on lusitania

2. unrestricted submarine warfare on American ships heading to Britain

3. Germany encouraged Mexico to attack the US

would it be plagiarism to copy and paste off of here? ?

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."