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: Zinc metal is produced using extractive metallurgy. After grinding the ore, froth flotation, which selectively separates minerals from gangue by taking advantage of differences in their hydrophobicity, is used to get an ore concentrate. This concentrate consists of about 50% zinc with the rest being sulfur (32%), iron (13%), and SiO
2 (5%). The composition of this is normally zinc sulfide (80% to 85%), iron sulfide (7.0% to 12%), lead sulfide (3.0% to 5.0%) silica (2.5% to 3.5%), and cadmium sulfide (0.35% to 0.41%).
[A]: What is used to eliminate the metal zinc?

[Q]: Passage: The southern side of Miami includes Coral Way, The Roads and Coconut Grove. Coral Way is a historic residential neighborhood built in 1922 connecting Downtown with Coral Gables, and is home to many old homes and tree-lined streets. Coconut Grove was established in 1825 and is the location of Miami's City Hall in Dinner Key, the Coconut Grove Playhouse, CocoWalk, many nightclubs, bars, restaurants and bohemian shops, and as such, is very popular with local college students. It is a historic neighborhood with narrow, winding roads, and a heavy tree canopy. Coconut Grove has many parks and gardens such as Villa Vizcaya, The Kampong, The Barnacle Historic State Park, and is the home of the Coconut Grove Convention Center and numerous historic homes and estates.
[A]: Along with Coconut Grove and Coral Way, what is notably unpresent in southern Miami?

[Q]: Passage: In 1987, occupations and units with the primary role of preparing for direct involvement in combat on the ground or at sea were still closed to women: infantry, armoured corps, field artillery, air-defence artillery, signals, field engineers, and naval operations. On 5 February 1987, the Minister of National Defence created an office to study the impact of employing men and women in combat units. These trials were called Combat-Related Employment of Women.
[A]:
Name some of the teaching opportunities in the CAF off limits to women in the 1980s.