What are some events from the past that are in some form happening again today?

What event brought the us into wwii? what conflicts happened after the us entered the war? i know the first part of this question, i need with the second part.

Explain the difference between the prosecutor in a criminal case and the prosecutor in a civil case.

How are the republican and democratic presidential candidates chosen? a. they are nominated by their state governments. b. each is nominated by his or her respective party. c. each is chosen by the governor of his or her home state. d. they are chosen by the house of representatives.