Problem: Railway electrification system:

Central station electricity can often be generated with higher efficiency than a mobile engine/generator. While the efficiency of power plant generation and diesel locomotive generation are roughly the same in the nominal regime, diesel motors decrease in efficiency in non-nominal regimes at low power while if an electric power plant needs to generate less power it will shut down its least efficient generators, thereby increasing efficiency. The electric train can save energy (as compared to diesel) by regenerative braking and by not needing to consume energy by idling as diesel locomotives do when stopped or coasting. However, electric rolling stock may run cooling blowers when stopped or coasting, thus consuming energy.

How can electric power plant become more power efficient?
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A: it will shut down its least efficient generators

Problem: Qing dynasty:

In 1725 Yongzheng bestowed the hereditary title of Marquis on a descendant of the Ming dynasty Imperial family, Zhu Zhiliang, who received a salary from the Qing government and whose duty was to perform rituals at the Ming tombs, and was also inducted the Chinese Plain White Banner in the Eight Banners. Later the Qianlong Emperor bestowed the title Marquis of Extended Grace posthumously on Zhu Zhuliang in 1750, and the title passed on through twelve generations of Ming descendants until the end of the Qing dynasty.

What was Zhu's job?
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A: perform rituals

Problem: Crucifixion of Jesus:

In Mark 15:25 crucifixion takes place at the third hour (9 a.m.) and Jesus' death at the ninth hour (3 p.m.). However, in John 19:14 Jesus is still before Pilate at the sixth hour. Scholars have presented a number of arguments to deal with the issue, some suggesting a reconciliation, e.g., based on the use of Roman timekeeping in John but not in Mark, yet others have rejected the arguments. Several notable scholars have argued that the modern precision of marking the time of day should not be read back into the gospel accounts, written at a time when no standardization of timepieces, or exact recording of hours and minutes was available, and time was often approximated to the closest three-hour period.

What did Pilate want with the Roman empire?
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A: unanswerable

Problem: Immaculate Conception:

The popularity of this particular representation of The Immaculate Conception spread across the rest of Europe, and has since remained the best known artistic depiction of the concept: in a heavenly realm, moments after her creation, the spirit of Mary (in the form of a young woman) looks up in awe at (or bows her head to) God. The moon is under her feet and a halo of twelve stars surround her head, possibly a reference to "a woman clothed with the sun" from Revelation 12:1-2. Additional imagery may include clouds, a golden light, and cherubs. In some paintings the cherubim are holding lilies and roses, flowers often associated with Mary.

What is under the feet of the Cherubs?
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A:
unanswerable