Input: High-definition television
The limited standardization of analog HDTV in the 1990s did not lead to global HDTV adoption as technical and economic constraints at the time did not permit HDTV to use bandwidths greater than normal television.

What constraints kept HDTV from being widely adopted in the 90's?
Output: technical and economic

Input: Article: Pain is the most common reason for people to use complementary and alternative medicine. An analysis of the 13 highest quality studies of pain treatment with acupuncture, published in January 2009, concluded there is little difference in the effect of real, sham and no acupuncture. However other reviews have found benefit. Additionally, there is tentative evidence for a few herbal medicine. There is interest in the relationship between vitamin D and pain, but the evidence so far from controlled trials for such a relationship, other than in osteomalacia, is unconvincing.

Now answer this question: Other than in osteomalacia, what is there no evidence of a relationship between pain and?

Output: vitamin D

Article: It is not only the proportion of latewood, but also its quality, that counts. In specimens that show a very large proportion of latewood it may be noticeably more porous and weigh considerably less than the latewood in pieces that contain but little. One can judge comparative density, and therefore to some extent strength, by visual inspection.

Question: What can we judge in wood just by looking at it?
Ans: comparative density

Here is a question about this article: The freedom to form, declare membership in, or campaign for candidates from a political party is considered a measurement of a state's adherence to liberal democracy as a political value. Regulation of parties may run from a crackdown on or repression of all opposition parties, a norm for authoritarian governments, to the repression of certain parties which hold or promote ideals which run counter to the general ideology of the state's incumbents (or possess membership by-laws which are legally unenforceable).
What is the answer to this question: How are parties regulated?
****
So... a crackdown on or repression of all opposition parties

The problem: Answer a question about this article:
Zen Buddhism (), pronounced Chan in Chinese, seon in Korean or zen in Japanese (derived from the Sanskrit term dhyana, meaning "meditation") is a form of Buddhism that became popular in China, Korea and Japan and that lays special emphasis on meditation.[note 12] Zen places less emphasis on scriptures than some other forms of Buddhism and prefers to focus on direct spiritual breakthroughs to truth.
Zen Buddhism is known as what in Korea?
****
The answer: seon

The problem: Answer a question about this article:
By the 20th century, the saloon, or lounge bar, had become a middle-class room[citation needed]carpets on the floor, cushions on the seats, and a penny or two on the prices,[citation needed] while the public bar, or tap room, remained working class with bare boards, sometimes with sawdust to absorb the spitting and spillages (known as "spit and sawdust"), hard bench seats, and cheap beer[citation needed]. This bar was known as the four-ale bar from the days when the cheapest beer served there cost 4 pence (4d) a quart.[citation needed]
What economic class was most likely to be found in the tap room?
****
The answer:
working class