Why do boundaries between states cause problems

Where is the only location in the united states where you drive on the left side of the road?

[ou.01]which of these is the most likely use of an electromagnetic wave which has wavelength shorter than microwaves but longer than visible light? o heat food safely o neat food safely o take images of bones and teeth o transmit radio and cellular phone signals o take images of bones and teeth o transmit radio and cellular phone signals o detect the location of objects which emit heat

Are divergent boundaries responsible for tsunamis?