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.
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Question: 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]

Answer: What time cycle did studies in 1938 and 1990s use on humans?


Question: The joint mission began when Soyuz 19 was first launched on July 15, 1975 at 12:20 UTC, and the Apollo craft was launched with the docking module six and a half hours later. The two craft rendezvoused and docked on July 17 at 16:19 UTC. The three astronauts conducted joint experiments with the two cosmonauts, and the crew shook hands, exchanged gifts, and visited each other's craft.

Answer: Soyuz 19 took off from Earth on what date?


Question: A common misperception is that the Supreme Court is the only court that may determine constitutionality; the power is exercised even by the inferior courts. But only Supreme Court decisions are binding across the nation. Decisions of a Court of Appeals, for instance, are binding only in the circuit over which the court has jurisdiction.

Answer:
Which courts decisions are binding across the entire United States?