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: Uranium carbides and uranium nitrides are both relatively inert semimetallic compounds that are minimally soluble in acids, react with water, and can ignite in air to form U
3O
8. Carbides of uranium include uranium monocarbide (UC), uranium dicarbide (UC
2), and diuranium tricarbide (U
2C
3). Both UC and UC
2 are formed by adding carbon to molten uranium or by exposing the metal to carbon monoxide at high temperatures. Stable below 1800 °C, U
2C
3 is prepared by subjecting a heated mixture of UC and UC
2 to mechanical stress. Uranium nitrides obtained by direct exposure of the metal to nitrogen include uranium mononitride (UN), uranium dinitride (UN
2), and diuranium trinitride (U
2N
3).

SOLUTION: Along with uranium monocarbide and uranium dicarbide, what is a unnotable carbide of uranium?

PROBLEM: Passage: The Slavic autonym *Slověninъ is usually considered (e.g. by Roman Jakobson) a derivation from slovo "word", originally denoting "people who speak (the same language)," i.e. people who understand each other, in contrast to the Slavic word denoting "foreign people" – němci, meaning "mumbling, murmuring people" (from Slavic *němъ – "mumbling, mute").

SOLUTION: Who came up with the Slavic autonym?

PROBLEM: Passage: After August 2008 sites had to be listed on the Open Directory in order to be included. According to Jeff Kaplan of the Internet Archive in November 2010, other sites were still being archived, but more recent captures would become visible only after the next major indexing, an infrequent operation.

SOLUTION:
When did it become a requirement for websites to appear on Open Directory for inclusion in Kaplan?

