The five democratic presidents are:
John Fitzgerald Kennedy (1961-1963)
Lyndon Baines Johnson (1963-1969)
Franklin Delano Roosevelt (1933-1945)
Harry S. Truman (1945-1953)
and James Buchanan, Jr. (1857-1861)
Answer:
It was caused by an H1N1 influenza A virus that scientists believe mutated from an influenza virus that was previously infecting only birds. It evolved and changed enough that it was able to infect humans and spread rapidly from person to person.
Explanation: