What us state traditionally holds the first contest to choose each major party's presidential nominee?

b) trade is easy because of the direct line between their major ports. bilateral trade reached 89,6 thousand million.

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."