NEED HELP ASAP PLZ

Restricting immigrants from entering a country may be based on what belief?  

Steven spielberg's classic movie jaws was a thriller about a great white shark that terrorized tourists at a local beach. just before the shark's appearance, eerie music began playing. as the unseen shark came closer, the tempo of the music picked up. after the audience had experienced this a few times, the sound of the music triggered the emotional reaction of fear in the audience even though the shark still had not appeared. at that point, the sound of the eerie music was a: a) unconditioned response (ucr) b) conditioned response (cr) c) conditioned stimulus (cs) d) unconditioned stimulus (ucs)

How did the percentage of americans living on farms change between 1820 and 1850 a. it lowered as many americans were sold into slavery b. it rated the same as people stopped coming to america c. it grew as more people came to america d. it lowered as many americans went to work in factories