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 do epithelial cells have at the oral end? 
 disfluent question: What do streamlines have at the oral end no what do epithelial cells have at the oral end? 
 context: The Beroida, also known as Nuda, have no feeding appendages, but their large pharynx, just inside the large mouth and filling most of the saclike body, bears macrocilia at the oral end. These fused bundles of several thousand large cilia are able to bite off pieces of prey that are too large to swallow whole – almost always other ctenophores. In front of the field of macrocilia, on the mouth lips in some species of Beroe, is a pair of narrow strips of adhesive epithelial cells on the stomach wall that zip the mouth shut when the animal is not feeding, by forming intercellular connections with the opposite adhesive strip. This tight closure streamlines the front of the animal when it is pursuing prey.
Example Output: None

Example Input: proper question: What requires collaboration across zoning requirements? 
 disfluent question: What requires construction umm I mean collaboration across zoning requirements? 
 context: Large-scale construction requires collaboration across multiple disciplines. An architect normally manages the job, and a construction manager, design engineer, construction engineer or project manager supervises it. For the successful execution of a project, effective planning is essential. Those involved with the design and execution of the infrastructure in question must consider zoning requirements, the environmental impact of the job, the successful scheduling, budgeting, construction-site safety, availability and transportation of building materials, logistics, inconvenience to the public caused by construction delays and bidding, etc. The largest construction projects are referred to as megaprojects.
Example Output: None

Example Input: proper question: How many chosen numbers exist? 
 disfluent question: Who established or how many chosen numbers exist? 
 context: There are infinitely many primes, as demonstrated by Euclid around 300 BC. There is no known simple formula that separates prime numbers from composite numbers. However, the distribution of primes, that is to say, the statistical behaviour of primes in the large, can be modelled. The first result in that direction is the prime number theorem, proven at the end of the 19th century, which says that the probability that a given, randomly chosen number n is prime is inversely proportional to its number of digits, or to the logarithm of n.
Example Output:
None