Students at a major university must go through several registration steps. officials have observed that it is typically the case that the waiting line at the fee-payment station is the longest. this would seem to suggest that the fee-payment station is the in the student registration process.

   Bottleneck

Explanation:  Bottleneck is a term used to describe a narrower part of a road or a track or an intersection that comes after the usual wider part of the road and which impedes the usual flow of traffic, thus slowing it down. In this case, due to the increased activity of students during registration process, the waiting line at the fee-payment station is the longest, there is a disruption at this line to the students flow, whether due to the slowness of the worker performing it, or for some other reason, the fact that there is a disruption in the flow students, i.e bottleneck.

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.        

the answer is solomon northrup. he was a free-born african american, abolitionist and professional violinist that was drugged, kidnapped and sold as slave in 1841 and remained in captivity until 1853 where he regained his freedom with the of the then-governor of new york, washington hunt. he wrote and published his memoirs "twelve years a slave" in 1853, and in this text, he tells the story of his escape thru one of louisiana's swamps (the great pacoudrie swamp) in which he ended up covered in green slime from crossing the surface of the dead water.