TASK DEFINITION: This task is about creating an unanswerable question based on a given passage. Construct a question that looks relevant to the given context but is unanswerable. Following are a few suggestions about how to create unanswerable questions:
(i) create questions which require satisfying a constraint that is not mentioned in the passage
(ii) create questions which require information beyond what is provided in the passage in order to answer
(iii) replace an existing entity, number, date mentioned in the passage with other entity, number, date and use it in the question
(iv) create a question which is answerable from the passage and then replace one or two words by their antonyms or insert/remove negation words to make it unanswerable.
PROBLEM: Passage: The divisions between all these groups are approximate and their boundaries are not always clear. The Mizrahim for example, are a heterogeneous collection of North African, Central Asian, Caucasian, and Middle Eastern Jewish communities that are no closer related to each other than they are to any of the earlier mentioned Jewish groups. In modern usage, however, the Mizrahim are sometimes termed Sephardi due to similar styles of liturgy, despite independent development from Sephardim proper. Thus, among Mizrahim there are Egyptian Jews, Iraqi Jews, Lebanese Jews, Kurdish Jews, Libyan Jews, Syrian Jews, Bukharian Jews, Mountain Jews, Georgian Jews, Iranian Jews and various others. The Teimanim from Yemen are sometimes included, although their style of liturgy is unique and they differ in respect to the admixture found among them to that found in Mizrahim. In addition, there is a differentiation made between Sephardi migrants who established themselves in the Middle East and North Africa after the expulsion of the Jews from Spain and Portugal in the 1490s and the pre-existing Jewish communities in those regions.

SOLUTION: What is always clear between these groups?

PROBLEM: Passage: Selenizza is a naturally occurring solid hydrocarbon bitumen found in the native asphalt deposit of Selenice, in Albania, the only European asphalt mine still in use. The rock asphalt is found in the form of veins, filling cracks in a more or less horizontal direction. The bitumen content varies from 83% to 92% (soluble in carbon disulphide), with a penetration value near to zero and a softening point (ring & ball) around 120 °C. The insoluble matter, consisting mainly of silica ore, ranges from 8% to 17%.

SOLUTION: The soluble matter consists mainly of silica ore and ranges from what percentage?

PROBLEM: Passage: In the Papal States, which existed until 1870, Jews were required to live only in specified neighborhoods called ghettos. In the 19th and (before the end of World War II) 20th centuries, the Roman Catholic Church adhered to a distinction between "good antisemitism" and "bad antisemitism". The "bad" kind promoted hatred of Jews because of their descent. This was considered un-Christian because the Christian message was intended for all of humanity regardless of ethnicity; anyone could become a Christian. The "good" kind criticized alleged Jewish conspiracies to control newspapers, banks, and other institutions, to care only about accumulation of wealth, etc.

SOLUTION:
What existed after 1870?