Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
Speculation that the Ashkenazi arose from Khazar stock surfaced in the later 19th century and has met with mixed fortunes in the scholarly literature. In late 2012 Eran Elhaik, a research associate studying genetics at the Johns Hopkins University School of Public Health, argued for Khazar descent in his paper The Missing Link of Jewish European Ancestry: Contrasting the Rhineland and the Khazarian Hypotheses. A 2013 study of Ashkenazi mitochondrial DNA found no significant evidence of Khazar contribution to the Ashkenazi Jewish DNA, as would be predicted by the Khazar hypothesis.
When did the idea that the Ashkenazi may have come from Khazar stock come about?
A: in the later 19th century

Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
Charles Babbage, an English mechanical engineer and polymath, originated the concept of a programmable computer. Considered the "father of the computer", he conceptualized and invented the first mechanical computer in the early 19th century. After working on his revolutionary difference engine, designed to aid in navigational calculations, in 1833 he realized that a much more general design, an Analytical Engine, was possible. The input of programs and data was to be provided to the machine via punched cards, a method being used at the time to direct mechanical looms such as the Jacquard loom. For output, the machine would have a printer, a curve plotter and a bell. The machine would also be able to punch numbers onto cards to be read in later. The Engine incorporated an arithmetic logic unit, control flow in the form of conditional branching and loops, and integrated memory, making it the first design for a general-purpose computer that could be described in modern terms as Turing-complete.
Who is considered the "father of the computer"?
A: Charles Babbage

Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
Western Armenian has a two-way distinction between aspirated and voiced: /t d/. Western Armenian aspirated /t/ corresponds to Eastern Armenian aspirated /t/ and voiced /d/, and Western voiced /d/ corresponds to Eastern voiceless /t/.
Western Armenian /t/ compares to eastern Armenian /t/ and what?
A: /d/

Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
Machine vision systems often require bright and homogeneous illumination, so features of interest are easier to process. LEDs are often used for this purpose, and this is likely to remain one of their major uses until the price drops low enough to make signaling and illumination uses more widespread. Barcode scanners are the most common example of machine vision, and many low cost products use red LEDs instead of lasers. Optical computer mice are an example of LEDs in machine vision, as it is used to provide an even light source on the surface for the miniature camera within the mouse. LEDs constitute a nearly ideal light source for machine vision systems for several reasons:
non-LEDs are often used for what type of systems?
A:
unanswerable