49. the answer is...

serve on a jury
vote in a federal election

Two responsibilities of U.S. citizens are to serve on a jury and vote in federal elections. The Constitution gives citizens the right to a trial by a jury. The jury is made up of U.S. citizens. Participation of citizens on a jury helps ensure a fair trial. Another important responsibility of citizens is voting. The law does not require citizens to vote, but voting is a very important part of any democracy. By voting, citizens are participating in the democratic process. Citizens vote for leaders to represent them and their ideas, and the leaders support the citizens’ interests.