This task is about reading the given passage and construct a question about the information present in the passage. Construct a question in such a way that (i) it is unambiguous, (ii) it is answerable from the passage, (iii) its answer is unique (iv) its answer is a continuous text span from the paragraph. Avoid creating questions that (i) can be answered correctly without actually understanding the paragraph and (ii) uses same words or phrases given in the passage.

Q: Recently, the Air Force refined its understanding of the core duties and responsibilities it performs as a Military Service Branch, streamlining what previously were six distinctive capabilities and seventeen operational functions into twelve core functions to be used across the doctrine, organization, training, equipment, leadership, and education, personnel, and facilities spectrum. These core functions express the ways in which the Air Force is particularly and appropriately suited to contribute to national security, but they do not necessarily express every aspect of what the Air Force contributes to the nation. It should be emphasized that the core functions, by themselves, are not doctrinal constructs.

A: How many core functions did the Air Force reduce its duties down to recently?
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Q: Guinea-Bissau's GDP per capita is one of the lowest in the world, and its Human Development Index is one of the lowest on earth. More than two-thirds of the population lives below the poverty line. The economy depends mainly on agriculture; fish, cashew nuts and ground nuts are its major exports.

A: How much of the population lives below the poverty line?
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Q: To Popper, who was an anti-justificationist, traditional philosophy is misled by the false principle of sufficient reason. He thinks that no assumption can ever be or needs ever to be justified, so a lack of justification is not a justification for doubt. Instead, theories should be tested and scrutinised. It is not the goal to bless theories with claims of certainty or justification, but to eliminate errors in them. He writes, "there are no such things as good positive reasons; nor do we need such things [...] But [philosophers] obviously cannot quite bring [themselves] to believe that this is my opinion, let alone that it is right" (The Philosophy of Karl Popper, p. 1043)

A:
According to Popper, what is not grounds for doubt?
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