In the significance of the frontier in american history, frederick jackson turner wrote :
“the frontier has gone, and with its going has closed the first period of american history”
how did advocates of expansionism react to turner's frontier thesis?
a. they argued americans should move from rural areas to expand the nation's new frontier--othe cities,
b. they argued congress should enact new protections for america's natural resources to rebuild the frontier
c. they argued americans should seek new lands overseas as a "safety valve" to release popular discontent.
d. they argued americans should turn away from the culture of the american west and embrace european culture

Why are constitutions, both federal and state, necessary for our government?

Why is it useful for historians to base certain studies on the analysis of historical periods

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.