Which of the following was a reason the us adopted a policy of isolation before world war ii

Which statement is an example of direct democracy? a) people elect a senator to the u.s. congress. b) the town council approves funding for a new high school. c) the president issues an executive preventing states from executing prisoners. d) voters approve an amendment allowing elderly people to pay nothing in property tax.

Which factor has played the most important role in changing the way history is studied over time?

What are the biggest challenges facing the average american citizen today? explain.