instruction:
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.
question:
proper question: How was the Black Death spread in Europe? 
 disfluent question: How was the transfer of disease through fleas er Black Death spread in Europe? 
 context: In addition to arguing that the rat population was insufficient to account for a bubonic plague pandemic, sceptics of the bubonic plague theory point out that the symptoms of the Black Death are not unique (and arguably in some accounts may differ from bubonic plague); that transference via fleas in goods was likely to be of marginal significance; and that the DNA results may be flawed and might not have been repeated elsewhere, despite extensive samples from other mass graves. Other arguments include the lack of accounts of the death of rats before outbreaks of plague between the 14th and 17th centuries; temperatures that are too cold in northern Europe for the survival of fleas; that, despite primitive transport systems, the spread of the Black Death was much faster than that of modern bubonic plague; that mortality rates of the Black Death appear to be very high; that, while modern bubonic plague is largely endemic as a rural disease, the Black Death indiscriminately struck urban and rural areas; and that the pattern of the Black Death, with major outbreaks in the same areas separated by 5 to 15 years, differs from modern bubonic plague—which often becomes endemic for decades with annual flare-ups.
answer:
None


question:
proper question: When do antibodies not circulate in? 
 disfluent question: When do offspring secrete no when do antibodies not circulate in? 
 context: A B cell identifies pathogens when antibodies on its surface bind to a specific foreign antigen. This antigen/antibody complex is taken up by the B cell and processed by proteolysis into peptides. The B cell then displays these antigenic peptides on its surface MHC class II molecules. This combination of MHC and antigen attracts a matching helper T cell, which releases lymphokines and activates the B cell. As the activated B cell then begins to divide, its offspring (plasma cells) secrete millions of copies of the antibody that recognizes this antigen. These antibodies circulate in blood plasma and lymph, bind to pathogens expressing the antigen and mark them for destruction by complement activation or for uptake and destruction by phagocytes. Antibodies can also neutralize challenges directly, by binding to bacterial toxins or by interfering with the receptors that viruses and bacteria use to infect cells.
answer:
None


question:
proper question: Which is less costly, formal, or informal imperialism? 
 disfluent question: Which is containing perceivable kinds of dominance no um which still less costly, formal, or informal imperialism? 
 context: The definition of imperialism has not been finalized for centuries and was confusedly seen to represent the policies of major powers, or simply, general-purpose aggressiveness. Further on, some writers[who?] used the term imperialism, in slightly more discriminating fashion, to mean all kinds of domination or control by a group of people over another. To clear out this confusion about the definition of imperialism one could speak of formal and informal imperialism, the first meaning physical control or full-fledged colonial rule while the second implied less direct rule though still containing perceivable kinds of dominance. Informal rule is generally less costly than taking over territories formally. This is because, with informal rule, the control is spread more subtly through technological superiority, enforcing land officials into large debts that cannot be repaid, ownership of private industries thus expanding the controlled area, or having countries agree to uneven trade agreements forcefully.
answer:

None