2. Why was the launch of Sputnik I in 1957 so significant? What did its launch mean for Americans?

Explanation:

On October 4, 1957, the Soviet Union launched the earth's first artificial satellite, Sputnik I. As a result, the launch of Sputnik served to intensify the arms race and raise Cold War tensions. During the 1950s, both the United States and the Soviet Union were working to develop new technology.

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."

nothing

hope this !