Use a disfluent question or a proper question and find the answer to the question based on the given context or return None if an answer can't be found. A disfluent question is a question that has some interruptions in it while framing. A proper question is the correct form of the question without any disfluency.

proper question: What are the phagocytes that are located in tissues in contact with the external environment called? 
 disfluent question: Which are the or no make that what are the phagocytes that are located in tissues in contact with the external environment called? 
 context: Dendritic cells (DC) are phagocytes in tissues that are in contact with the external environment; therefore, they are located mainly in the skin, nose, lungs, stomach, and intestines. They are named for their resemblance to neuronal dendrites, as both have many spine-like projections, but dendritic cells are in no way connected to the nervous system. Dendritic cells serve as a link between the bodily tissues and the innate and adaptive immune systems, as they present antigens to T cells, one of the key cell types of the adaptive immune system.
Dendritic cells

proper question: Who was the university's 5th president? 
 disfluent question: Who was the hospital's, oh gosh, I mean university's 5th president? 
 context: In 1929, the university's fifth president, Robert Maynard Hutchins, took office; the university underwent many changes during his 24-year tenure. Hutchins eliminated varsity football from the university in an attempt to emphasize academics over athletics, instituted the undergraduate college's liberal-arts curriculum known as the Common Core, and organized the university's graduate work into its current[when?] four divisions. In 1933, Hutchins proposed an unsuccessful plan to merge the University of Chicago and Northwestern University into a single university. During his term, the University of Chicago Hospitals (now called the University of Chicago Medical Center) finished construction and enrolled its first medical students. Also, the Committee on Social Thought, an institution distinctive of the university, was created.
Robert Maynard Hutchins

proper question: What were select locations connected to? 
 disfluent question: Who were no uh make that what were selected locations connected to? 
 context: The Very high-speed Backbone Network Service (vBNS) came on line in April 1995 as part of a National Science Foundation (NSF) sponsored project to provide high-speed interconnection between NSF-sponsored supercomputing centers and select access points in the United States. The network was engineered and operated by MCI Telecommunications under a cooperative agreement with the NSF. By 1998, the vBNS had grown to connect more than 100 universities and research and engineering institutions via 12 national points of presence with DS-3 (45 Mbit/s), OC-3c (155 Mbit/s), and OC-12c (622 Mbit/s) links on an all OC-12c backbone, a substantial engineering feat for that time. The vBNS installed one of the first ever production OC-48c (2.5 Gbit/s) IP links in February 1999 and went on to upgrade the entire backbone to OC-48c.

None

