4. Which of these happened first?
A)The first flu vaccine was developed.
B)A soldier showed up with the flu at an Army
base in Kansas.
C)World War I began.
D)About 200,000 people attended a parade
in Philadelphia to support the war effort.
Explanation: The World War 1 is what made the Flu become forgotten about/ overshadowed the reason the whole frlu started was because a soldier walked into a Army camp.
