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: There is no natural source for green food colorings which has been approved by the US Food and Drug Administration. Chlorophyll, the E numbers E140 and E141, is the most common green chemical found in nature, and only allowed in certain medicines and cosmetic materials. Quinoline Yellow (E104) is a commonly used coloring in the United Kingdom but is banned in Australia, Japan, Norway and the United States. Green S (E142) is prohibited in many countries, for it is known to cause hyperactivity, asthma, urticaria, and insomnia.

SOLUTION: Which two E numbers have been approved by the FDA?

PROBLEM: Passage: The formation of the party was formally announced at Sydney Town Hall on 31 August 1945. It took the name "Liberal" in honour of the old Commonwealth Liberal Party. The new party was dominated by the remains of the old UAP; with few exceptions, the UAP party room became the Liberal party room. The Australian Women's National League, a powerful conservative women's organisation, also merged with the new party. A conservative youth group Menzies had set up, the Young Nationalists, was also merged into the new party. It became the nucleus of the Liberal Party's youth division, the Young Liberals. By September 1945 there were more than 90,000 members, many of whom had not previously been members of any political party.

SOLUTION: Where was the formation of the UAP party officially announced?

PROBLEM: Passage: Glacial ice is the largest reservoir of freshwater on Earth. Many glaciers from temperate, alpine and seasonal polar climates store water as ice during the colder seasons and release it later in the form of meltwater as warmer summer temperatures cause the glacier to melt, creating a water source that is especially important for plants, animals and human uses when other sources may be scant. Within high altitude and Antarctic environments, the seasonal temperature difference is often not sufficient to release meltwater.

SOLUTION:
Where is all the fresh water on earth contained?