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: The Cambridge Rules, first drawn up at Cambridge University in 1848, were particularly influential in the development of subsequent codes, including association football. The Cambridge Rules were written at Trinity College, Cambridge, at a meeting attended by representatives from Eton, Harrow, Rugby, Winchester and Shrewsbury schools. They were not universally adopted. During the 1850s, many clubs unconnected to schools or universities were formed throughout the English-speaking world, to play various forms of football. Some came up with their own distinct codes of rules, most notably the Sheffield Football Club, formed by former public school pupils in 1857, which led to formation of a Sheffield FA in 1867. In 1862, John Charles Thring of Uppingham School also devised an influential set of rules.

A: Which rules were influential to the codes of association football?
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Q: Studies by Nathaniel Kleitman in 1938 and by Derk-Jan Dijk and Charles Czeisler in the 1990s put human subjects on enforced 28-hour sleep–wake cycles, in constant dim light and with other time cues suppressed, for over a month. Because normal people cannot entrain to a 28-hour day in dim light if at all,[citation needed] this is referred to as a forced desynchrony protocol. Sleep and wake episodes are uncoupled from the endogenous circadian period of about 24.18 hours and researchers are allowed to assess the effects of circadian phase on aspects of sleep and wakefulness including sleep latency and other functions.[page needed]

A: What time cycle did studies in 1938 and 1990s use on humans?
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Q: The North American mnemonic "spring forward, fall back" (also "spring ahead ...", "spring up ...", and "... fall behind") helps people remember which direction to shift clocks.

A:
What phrase is often used in North America when speaking about DST?
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