Answer:
d
Explanation:
long periods of time occur in between and important events may happen during these times
Which war? WWI: We were isolationists until illegal German U-boats sank a United States commercial ship called the Lusitania.
WWII: We were isolationists until December 7, 1941 when the Japanese air fleet surprise attacked and bombed us at Pearl Harbor.
Art, math, science, maybe psychology
