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.
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Question: Passage: Terra preta (black earth), which is distributed over large areas in the Amazon forest, is now widely accepted as a product of indigenous soil management. The development of this fertile soil allowed agriculture and silviculture in the previously hostile environment; meaning that large portions of the Amazon rainforest are probably the result of centuries of human management, rather than naturally occurring as has previously been supposed. In the region of the Xingu tribe, remains of some of these large settlements in the middle of the Amazon forest were found in 2003 by Michael Heckenberger and colleagues of the University of Florida. Among those were evidence of roads, bridges and large plazas.

Answer: Terra preta is distributor over a small area of what?

Question: Passage: If matter and energy are seen as necessary to explain the physical world, but incapable of explaining mind, dualism results. Emergence, holism, and process philosophy seek to ameliorate the perceived shortcomings of traditional (especially mechanistic) materialism without abandoning materialism entirely.

Answer: What is unnecessary to explain the physical world?

Question: Passage: From 22 March through 26 March 1991, mass pro-democracy rallies and a nationwide strike was held in both urban and rural communities, which became known as les evenements ("the events") or the March Revolution. In Bamako, in response to mass demonstrations organized by university students and later joined by trade unionists and others, soldiers opened fire indiscriminately on the nonviolent demonstrators. Riots broke out briefly following the shootings. Barricades as well as roadblocks were erected and Traore declared a state of emergency and imposed a nightly curfew. Despite an estimated loss of 300 lives over the course of four days, nonviolent protesters continued to return to Bamako each day demanding the resignation of the dictatorial president and the implementation of democratic policies.

Answer:
What was held in both urban and rural communities throughout the 1990s?