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.
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Question: Passage: Sichuan came under the firm control of a Chinese central government during the Sui dynasty, but it was during the subsequent Tang dynasty where Sichuan regained its previous political and cultural prominence for which it was known during the Han. Chengdu became nationally known as a supplier of armies and the home of Du Fu, who is sometimes called China's greatest poet. During the An Lushan Rebellion (755-763), Emperor Xuanzong of Tang fled from Chang'an to Sichuan. The region was torn by constant warfare and economic distress as it was besieged by the Tibetan Empire.

Answer: Who regained their prominence under the Sui dynasty?


Question: Passage: YouTube entered into a marketing and advertising partnership with NBC in June 2006. In November 2008, YouTube reached an agreement with MGM, Lions Gate Entertainment, and CBS, allowing the companies to post full-length films and television episodes on the site, accompanied by advertisements in a section for US viewers called "Shows". The move was intended to create competition with websites such as Hulu, which features material from NBC, Fox, and Disney. In November 2009, YouTube launched a version of "Shows" available to UK viewers, offering around 4,000 full-length shows from more than 60 partners. In January 2010, YouTube introduced an online film rentals service, which is available only to users in the US, Canada and the UK as of 2010. The service offers over 6,000 films.

Answer: Who entered into a partnership during June 2008 with NBC?


Question: Passage: As advances and specialization have made new scientific research inaccessible to most audiences, the "literary" nature of science writing has become less pronounced over the last two centuries. Now, science appears mostly in journals. Scientific works of Aristotle, Copernicus, and Newton still exhibit great value, but since the science in them has largely become outdated, they no longer serve for scientific instruction. Yet, they remain too technical to sit well in most programmes of literary study. Outside of "history of science" programmes, students rarely read such works.

Answer:
The literary nature of science writing has become more pronounced during what time period?