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.

Example Input: proper question: What started with a zero velocity? 
 disfluent question: What continues er what started with a zero velocity? 
 context: A simple case of dynamic equilibrium occurs in constant velocity motion across a surface with kinetic friction. In such a situation, a force is applied in the direction of motion while the kinetic friction force exactly opposes the applied force. This results in zero net force, but since the object started with a non-zero velocity, it continues to move with a non-zero velocity. Aristotle misinterpreted this motion as being caused by the applied force. However, when kinetic friction is taken into consideration it is clear that there is no net force causing constant velocity motion.
Example Output: None

Example Input: proper question: How large is the Pierre-Auguste Renoir piece? 
 disfluent question: What was wait no I mean how large is the Pierre-Auguste Renoir piece? 
 context: Fulton Street in Downtown Fresno was Fresno's main financial and commercial district before being converted into one of the nation's first pedestrian malls in 1964. Renamed the Fulton Mall, the area contains the densest collection of historic buildings in Fresno. While the Fulton Mall corridor has suffered a sharp decline from its heyday, the Mall includes some of the finest public art pieces in the country, including the only Pierre-Auguste Renoir piece in the world that one can walk up to and touch. Current plans call for the reopening of the Fulton Mall to automobile traffic. The public art pieces will be restored and placed near their current locations and will feature wide sidewalks (up to 28' on the east side of the street) to continue with the pedestrian friendly environment of the district.
Example Output: None

Example Input: proper question: What is an example of a less sophisticated defense mechanism that jawed vertebrates have? 
 disfluent question: Who is or no make what is an example of a less sophisticated defense mechanism that jawed vertebrates have? 
 context: Pathogens can rapidly evolve and adapt, and thereby avoid detection and neutralization by the immune system; however, multiple defense mechanisms have also evolved to recognize and neutralize pathogens. Even simple unicellular organisms such as bacteria possess a rudimentary immune system, in the form of enzymes that protect against bacteriophage infections. Other basic immune mechanisms evolved in ancient eukaryotes and remain in their modern descendants, such as plants and invertebrates. These mechanisms include phagocytosis, antimicrobial peptides called defensins, and the complement system. Jawed vertebrates, including humans, have even more sophisticated defense mechanisms, including the ability to adapt over time to recognize specific pathogens more efficiently. Adaptive (or acquired) immunity creates immunological memory after an initial response to a specific pathogen, leading to an enhanced response to subsequent encounters with that same pathogen. This process of acquired immunity is the basis of vaccination.
Example Output:
None