Problem: Geography of the United States:

The Laurentian Highlands, the Interior Plains and the Interior Highlands lie between the two coasts, stretching from the Gulf of Mexico northward, far beyond the national boundary, to the Arctic Ocean. The central plains are divided by a hardly perceptible height of land into a Canadian and a United States portion. It is from the United States side, that the great Mississippi system discharges southward to the Gulf of Mexico. The upper Mississippi and some of the Ohio basin is the semi-arid prairie region, with trees originally only along the watercourses. The uplands towards the Appalachians were included in the great eastern forested area, while the western part of the plains has so dry a climate that its native plant life is scanty, and in the south it is practically barren.

Originally trees covered all of what?
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A: unanswerable

Problem: The world of clothing is always changing, as new cultural influences meet technological innovations. Researchers in scientific labs have been developing prototypes for fabrics that can serve functional purposes well beyond their traditional roles, for example, clothes that can automatically adjust their temperature, repel bullets, project images, and generate electricity. Some practical advances already available to consumers are bullet-resistant garments made with kevlar and stain-resistant fabrics that are coated with chemical mixtures that reduce the absorption of liquids.
What have researchers in science labs been making?
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Answer: prototypes

Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
Since the 1970s, an important focus of study has been the ozone layer in the atmosphere above Antarctica. In 1985, three British scientists working on data they had gathered at Halley Station on the Brunt Ice Shelf discovered the existence of a hole in this layer. It was eventually determined that the destruction of the ozone was caused by chlorofluorocarbons (CFCs) emitted by human products. With the ban of CFCs in the Montreal Protocol of 1989, climate projections indicate that the ozone layer will return to 1980 levels between 2050 and 2070.
What chemical was discovered to have caused the hole in the ozone?
A: chlorofluorocarbons

Context and question: The opposite of a Show Up is a "Rip". This is for sub-standard work, which is sometimes torn at the top of the page/sheet and must be submitted to the boy's housemaster for signature. Boys who accumulate rips are liable to be given a "White Ticket", which must be signed by all his teachers and may be accompanied by other punishments, usually involving doing domestic chores or writing lines. In recent times,[when?] a milder form of the rip, 'sign for information', colloquially known as an "info", has been introduced, which must also be signed by the boy's housemaster and tutor.
What action is colloquially known as a Show Up?
Answer: unanswerable

Question: Long before the exemption is considered by the Endangered Species Committee, the Forest Service, and either the FWS or the NMFS will have consulted on the biological implications of the timber harvest. The consultation can be informal, to determine if harm may occur; and then formal if the harm is believed to be likely. The questions to be answered in these consultations are whether the species will be harmed, whether the habitat will be harmed and if the action will aid or hinder the recovery of the listed species.
Is there an answer to this question: During informal consultation, what is the goal?

Answer: to determine if harm may occur

Problem: Iranian languages:

The geographical regions in which Iranian languages were spoken were pushed back in several areas by newly neighbouring languages. Arabic spread into some parts of Western Iran (Khuzestan), and Turkic languages spread through much of Central Asia, displacing various Iranian languages such as Sogdian and Bactrian in parts of what is today Turkmenistan, Uzbekistan and Tajikistan. In Eastern Europe, mostly comprising the territory of modern-day Ukraine, southern European Russia, and parts of the Balkans, the core region of the native Scythians, Sarmatians, and Alans had been decisively been taken over as a result of absorption and assimilation (e.g. Slavicisation) by the various Proto-Slavic population of the region, by the 6th century AD. This resulted in the displacement and extinction of the once predominant Scythian languages of the region. Sogdian's close relative Yaghnobi barely survives in a small area of the Zarafshan valley east of Samarkand, and Saka as Ossetic in the Caucasus, which is the sole remnant of the once predominant Scythian languages in Eastern Europe proper and large parts of the North Caucasus. Various small Iranian languages in the Pamirs survive that are derived from Eastern Iranian.

Ossetic is a version of which Scythian language?
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A:
Saka