In 1917, the Russian Revolution overthrew the tsar and contributed to Russia’s exit from the war.
The answer is A he was a former enslaved person who became a speaker
U.S. participation in NATO was a break with tradition, since the United States for the first time set itself up to automatically get involved in foreign conflicts--something that was very unnerving for a country of people who for most of American's history had been very isolationist.
I believe the answer is: positive externality
Positive externality refers to The benefit that enjoyed by a third party when the first and second party are conducting a transaction.
When you receive a vaccines, you prevent yourself from becoming a host that could contaminate other people from getting the virus. In the example above, you and your children are the first and second party. And other children are the third party.