Choose the statements that CORRECTLY describe the influenza Outbreak of 1918.
1. It was caused by new germs used in fighting World War I.
2. It is considered to have been a national epidemic.
3. It was referred to as the "Spanish Flu" by many at the time.
4. It affected mostly the elderly.
5. It is unknown as to exactly where the flu originated.
6. It killed more people than World War I.
7. It was eliminated after the government vaccinated soldiers returning from Europe.
Please explain if possible :)