Which key idea in the Constitution creates a division of power between national and state governments?

Read the excerpt below and answer the question. and i live on, but in grief and self-contempt, left here without the light i loved so much, in a great tempest and with shrouds unkempt. no more love songs, then, i have done with such; my old skill now runs thin at each attempt, and tears are heard within the harp i touch. (lines 9-14) which of the lines, taken from the sestet shown above, is the volta?

This is the only court in witch one state may sue another

One day as your professor is driving to work, another driver runs through a red light and hits his car. the professor is shaken up but survives the accident. however, the next time he starts to enter the intersection, he becomes nervous and fearful. soon, he starts going to work via another route to avoid the intersection even though this route adds twenty minutes to his commute in each direction. according to the principles of classical conditioning, why does the professor become scared of the previously harmless intersection? what can he do about this, as going via other route is very time consuming? be specific. break down the situation into its parts and show how the principles of learning apply.