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: External evidence is evidence of each physical witness, its date, source, and relationship to other known witnesses. Critics will often prefer the readings supported by the oldest witnesses. Since errors tend to accumulate, older manuscripts should have fewer errors. Readings supported by a majority of witnesses are also usually preferred, since these are less likely to reflect accidents or individual biases. For the same reasons, the most geographically diverse witnesses are preferred. Some manuscripts show evidence that particular care was taken in their composition, for example, by including alternative readings in their margins, demonstrating that more than one prior copy (exemplar) was consulted in producing the current one. Other factors being equal, these are the best witnesses. The role of the textual critic is necessary when these basic criteria are in conflict. For instance, there will typically be fewer early copies, and a larger number of later copies. The textual critic will attempt to balance these criteria, to determine the original text.

SOLUTION: External evidence is evidence of each physical witness, its date, source, relationship to other known witnesses, and what else? 

PROBLEM: Passage: This was also a period of alternatives to nightclubs, the warehouse party, acid house, rave and outdoor festival scenes of the late 1980s and early 1990s were havens for the latest trends in electronic dance music, especially house and its ever-more hypnotic, synthetic offspring techno and trance, in clubs like the infamous Warsaw Ballroom better known as Warsaw and The Mix where DJs like david padilla (who was the resident DJ for both) and radio. The new sound fed back into mainstream clubs across the country. The scene in SoBe, along with a bustling secondhand market for electronic instruments and turntables, had a strong democratizing effect, offering amateur, "bedroom" DJs the opportunity to become proficient and popular as both music players and producers, regardless of the whims of the professional music and club industries. Some of these notable DJs are John Benetiz (better known as JellyBean Benetiz), Danny Tenaglia, and David Padilla.

SOLUTION: Who was the Warsaw Ballroom's house JD?

PROBLEM: Passage: On July 22, 2008, in the aftermath of the Southwest Airlines inspection scandal, a bill was unanimously approved in the House to tighten regulations concerning airplane maintenance procedures, including the establishment of a whistleblower office and a two-year "cooling off" period that FAA inspectors or supervisors of inspectors must wait before they can work for those they regulated. The bill also required rotation of principal maintenance inspectors and stipulated that the word "customer" properly applies to the flying public, not those entities regulated by the FAA. The bill died in a Senate committee that year.

SOLUTION:
When did the Senate approve a bill to tighten regulations concerning airplane maintenance procedures?