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: In cases where the criminalized behavior is pure speech, civil disobedience can consist simply of engaging in the forbidden speech. An example would be WBAI's broadcasting the track "Filthy Words" from a George Carlin comedy album, which eventually led to the 1978 Supreme Court case of FCC v. Pacifica Foundation. Threatening government officials is another classic way of expressing defiance toward the government and unwillingness to stand for its policies. For example, Joseph Haas was arrested for allegedly sending an email to the Lebanon, New Hampshire city councilors stating, "Wise up or die."

SOLUTION: What did George Carlin send to the city council in New Hampshire?

PROBLEM: Passage: "Green" in modern European languages corresponds to about 520–570 nm, but many historical and non-European languages make other choices, e.g. using a term for the range of ca. 450–530 nm ("blue/green") and another for ca. 530–590 nm ("green/yellow").[citation needed] In the comparative study of color terms in the world's languages, green is only found as a separate category in languages with the fully developed range of six colors (white, black, red, green, yellow, and blue), or more rarely in systems with five colors (white, red, yellow, green, and black/blue). (See distinction of green from blue) These languages have introduced supplementary vocabulary to denote "green", but these terms are recognizable as recent adoptions that are not in origin color terms (much like the English adjective orange being in origin not a color term but the name of a fruit). Thus, the Thai word เขียว besides meaning "green" also means "rank" and "smelly" and holds other unpleasant associations.

SOLUTION: What does the Thai word for green correspond to in nm?

PROBLEM: Passage: The Somerset Coal Canal was built in the early 19th century to reduce the cost of transportation of coal and other heavy produce. The first 16 kilometres (10 mi), running from a junction with the Kennet and Avon Canal, along the Cam valley, to a terminal basin at Paulton, were in use by 1805, together with several tramways. A planned 11.7 km (7.3 mi) branch to Midford was never built, but in 1815 a tramway was laid along its towing path. In 1871 the tramway was purchased by the Somerset and Dorset Joint Railway (S&DJR), and operated until the 1950s.

SOLUTION:
Who built the Somerset Coal Canal?