instruction:
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.
question:
Passage: The meaning of federalism, as a political movement, and of what constitutes a 'federalist', varies with country and historical context.[citation needed] Movements associated with the establishment or development of federations can exhibit either centralising or decentralising trends.[citation needed] For example, at the time those nations were being established, factions known as "federalists" in the United States and Australia advocated the formation of strong central government. Similarly, in European Union politics, federalists mostly seek greater EU integration. In contrast, in Spain and in post-war Germany, federal movements have sought decentralisation: the transfer of power from central authorities to local units. In Canada, where Quebec separatism has been a political force for several decades, the "federalist" impulse aims to keep Quebec inside Canada.
answer:
What isn't the meaning of federalism?


question:
Passage: In 1987, in Canada, Elizabeth publicly supported politically divisive constitutional amendments, prompting criticism from opponents of the proposed changes, including Pierre Trudeau. The same year, the elected Fijian government was deposed in a military coup. Elizabeth, as monarch of Fiji, supported the attempts of the Governor-General, Ratu Sir Penaia Ganilau, to assert executive power and negotiate a settlement. Coup leader Sitiveni Rabuka deposed Ganilau and declared Fiji a republic. By the start of 1991, republican feeling in Britain had risen because of press estimates of the Queen's private wealth—which were contradicted by the Palace—and reports of affairs and strained marriages among her extended family. The involvement of the younger royals in the charity game show It's a Royal Knockout was ridiculed and the Queen was the target of satire.
answer:
What government was Pierre Trudeau prime minister of in 1987?


question:
Passage: During the Cretaceous, the late Paleozoic-early Mesozoic supercontinent of Pangaea completed its breakup into present day continents, although their positions were substantially different at the time. As the Atlantic Ocean widened, the convergent-margin orogenies that had begun during the Jurassic continued in the North American Cordillera, as the Nevadan orogeny was followed by the Sevier and Laramide orogenies. Though Gondwana was still intact in the beginning of the Cretaceous, Gondwana itself broke up as South America, Antarctica and Australia rifted away from Africa (though India and Madagascar remained attached to each other); thus, the South Atlantic and Indian Oceans were newly formed. Such active rifting lifted great undersea mountain chains along the welts, raising eustatic sea levels worldwide.
answer:

During what periods did Pangaea come together?