Input: Read this: Vacuum is useful in a variety of processes and devices. Its first widespread use was in the incandescent light bulb to protect the filament from chemical degradation. The chemical inertness produced by a vacuum is also useful for electron beam welding, cold welding, vacuum packing and vacuum frying. Ultra-high vacuum is used in the study of atomically clean substrates, as only a very good vacuum preserves atomic-scale clean surfaces for a reasonably long time (on the order of minutes to days). High to ultra-high vacuum removes the obstruction of air, allowing particle beams to deposit or remove materials without contamination. This is the principle behind chemical vapor deposition, physical vapor deposition, and dry etching which are essential to the fabrication of semiconductors and optical coatings, and to surface science. The reduction of convection provides the thermal insulation of thermos bottles. Deep vacuum lowers the boiling point of liquids and promotes low temperature outgassing which is used in freeze drying, adhesive preparation, distillation, metallurgy, and process purging. The electrical properties of vacuum make electron microscopes and vacuum tubes possible, including cathode ray tubes. The elimination of air friction is useful for flywheel energy storage and ultracentrifuges.
Question: What is produced by a vacuum and used in electron beam welding and vacuum frying?

Output: chemical inertness

QUES: Born in 1926, Harper Lee grew up in the Southern town of Monroeville, Alabama, where she became close friends with soon-to-be famous writer Truman Capote. She attended Huntingdon College in Montgomery (194445), and then studied law at the University of Alabama (194549). While attending college, she wrote for campus literary magazines: Huntress at Huntingdon and the humor magazine Rammer Jammer at the University of Alabama. At both colleges, she wrote short stories and other works about racial injustice, a rarely mentioned topic on such campuses at the time. In 1950, Lee moved to New York City, where she worked as a reservation clerk for British Overseas Airways Corporation; there, she began writing a collection of essays and short stories about people in Monroeville. Hoping to be published, Lee presented her writing in 1957 to a literary agent recommended by Capote. An editor at J. B. Lippincott , who bought the manuscript, advised her to quit the airline and concentrate on writing. Donations from friends allowed her to write uninterrupted for a year.

Who did Harper Lee become childhood friends with?
What is the answer?
ANS: Truman Capote

QUES: In the last years of the nineteenth century, Planck was investigating the problem of black-body radiation first posed by Kirchhoff some forty years earlier. It is well known that hot objects glow, and that hotter objects glow brighter than cooler ones. The electromagnetic field obeys laws of motion similarly to a mass on a spring, and can come to thermal equilibrium with hot atoms. The hot object in equilibrium with light absorbs just as much light as it emits. If the object is black, meaning it absorbs all the light that hits it, then its thermal light emission is maximized.
What was Planck studying in the last part of the nineteenth century?

ANS: the problem of black-body radiation

Genetic studies on Jews show that most Jews worldwide bear a common genetic heritage which originates in the Middle East, and that they bear their strongest resemblance to the peoples of the Fertile Crescent. The genetic composition of different Jewish groups shows that Jews share a common genetic pool dating back 4,000 years, as a marker of their common ancestral origin. Despite their long-term separation and beside their shared genetic origin, Jews also maintained a common culture, tradition, and language.
If it is possible to answer this question, answer it for me (else, reply "unanswerable"): Genetic studies show that Jews bear their strongest resemblance to the peoples of where?
Ah, so.. Fertile Crescent

Question: Railways must operate at variable speeds. Until the mid 1980s this was only practical with the brush-type DC motor, although such DC can be supplied from an AC catenary via on-board electric power conversion. Since such conversion was not well developed in the late 19th century and early 20th century, most early electrified railways used DC and many still do, particularly rapid transit (subways) and trams. Speed was controlled by connecting the traction motors in various series-parallel combinations, by varying the traction motors' fields, and by inserting and removing starting resistances to limit motor current.
Try to answer this question if possible: What is speed limit for railways?
Answer: variable speeds

Problem: The abbey's two western towers were built between 1722 and 1745 by Nicholas Hawksmoor, constructed from Portland stone to an early example of a Gothic Revival design. Purbeck marble was used for the walls and the floors of Westminster Abbey, even though the various tombstones are made of different types of marble. Further rebuilding and restoration occurred in the 19th century under Sir George Gilbert Scott.
Under whom did the 18th century rebulding occur?
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Answer:
unanswerable