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.
Answer:
September 11, 2001
Explanation:
The World Trade Center was destroyed following the terrorist attacks of September 11, 2001, when two hijacked commercial planes collided with the Twin Towers.
Answer:
Primarily disease working in conjunction with their weak immune systems.
Explanation:
Hope this helps!