Some central asian nomads made their living by fostering commerce along the silk road. central asian nomads invaded villages and cities when climate changes affected their food supply. some central asian nomads adopted islam and some embraced islamic cultures. based on these statements, which generalization about central asian nomads can best be supported?
1. they posed few challenges to settled societies.
2. they allied with settled neighbors to repel common enemies.
3. they interacted with settled societies.
4. they contributed little to the culture of their settled neighbors.

the fourth amendment protects:

"the right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated, and no warrants shall issue, but upon probable cause, supported by oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized."  

so this would mean the denial to search and seizure without warrant or permission.

this null effect is caused by a weak manipulation and ineffective internal validity. in a scientific study, as the one dr. morimoto is trying to perfom, internal validity refers to the confidence placed in the cause-effect relationship and to how well an experiment is done and able to eliminate confounding variables.