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.

[Q]: Passage: Several annual events—many of them centered on performing and visual arts—draw visitors to Ann Arbor. One such event is the Ann Arbor Art Fairs, a set of four concurrent juried fairs held on downtown streets. Scheduled on Wednesday through Saturday of the third week of July, the fairs draw upward of half a million visitors. Another is the Ann Arbor Film Festival, held during the third week of March, which receives more than 2,500 submissions annually from more than 40 countries and serves as one of a handful of Academy Award–qualifying festivals in the United States.
[A]: What festival receives more than 5,200 submissions annually?


[Q]: Passage: To be considered 'enriched', the uranium-235 fraction should be between 3% and 5%. This process produces huge quantities of uranium that is depleted of uranium-235 and with a correspondingly increased fraction of uranium-238, called depleted uranium or 'DU'. To be considered 'depleted', the uranium-235 isotope concentration should be no more than 0.3%. The price of uranium has risen since 2001, so enrichment tailings containing more than 0.35% uranium-235 are being considered for re-enrichment, driving the price of depleted uranium hexafluoride above $130 per kilogram in July 2007 from $5 in 2001.
[A]: Between what percent fraction range of uranium-235 is uranium regarded as unenriched?


[Q]: Passage: The sensitivity of Earth-based infrared telescopes is significantly limited by water vapor in the atmosphere, which absorbs a portion of the infrared radiation arriving from space outside of selected atmospheric windows. This limitation can be partially alleviated by placing the telescope observatory at a high altitude, or by carrying the telescope aloft with a balloon or an aircraft. Space telescopes do not suffer from this handicap, and so outer space is considered the ideal location for infrared astronomy.
[A]:
What limits the sensitivity of high altitude observatories?