1. except for north dakota, what
do states require citizens to
do before they vote?

Except for North Dakota, the remaining states require the citizens to register for voting before they vote.

Explanation:

In order to restrict the malpractices that are prevalent during voting, all the states across the United States except North Dakota need their citizens to register as a 'voter' to become eligible for voting. In the state of North Dakota, the only requirement that the voters need to fulfill is that of producing an identification proof to prove that they are a resident of North Dakota and are above 18 years of age.