Problem: The gut is generally an almost straight tube supported by the mesenteries (vertical partitions within segments), and ends with the anus on the underside of the pygidium. However, in members of the tube-dwelling family Siboglinidae the gut is blocked by a swollen lining that houses symbiotic bacteria, which can make up 15% of the worms' total weight. The bacteria convert inorganic matter such as hydrogen sulfide and carbon dioxide from hydrothermal vents, or methane from seeps to organic matter that feeds themselves and their hosts, while the worms extend their palps into the gas flows to absorb the gases needed by the bacteria.
What blocks the Siboglinidae's gut?
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Answer: a swollen lining

Problem: Politically, The Sun in the early Murdoch years, remained nominally Labour. It supported the Labour Party led by Harold Wilson in the 1970 General Election, with the headline "Why It Must Be Labour" but by February 1974 it was calling for a vote for the Conservative Party led by Edward Heath while suggesting that it might support a Labour Party led by James Callaghan or Roy Jenkins. In the October election an editorial asserted: "ALL our instincts are left rather than right and we would vote for any able politician who would describe himself as a Social Democrat."
What type of politician did a Sun editorial state that it would support in October 1974?
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Answer: any able politician who would describe himself as a Social Democrat

Problem: In 2004, philosopher and psychologist Michel ter Hark (Groningen, The Netherlands) published a book, called Popper, Otto Selz and the rise of evolutionary epistemology, in which he claimed that Popper took some of his ideas from his tutor, the German psychologist Otto Selz. Selz never published his ideas, partly because of the rise of Nazism, which forced him to quit his work in 1933, and the prohibition of referring to Selz' work. Popper, the historian of ideas and his scholarship, is criticised in some academic quarters for his rejection of Plato, Hegel and Marx.
Why did Selz publish his ideas?
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Answer:
unanswerable