Problem: Predation:

The elimination of wolves from Yellowstone National Park had profound impacts on the trophic pyramid. Without predation, herbivores began to over-graze many woody browse species, affecting the area's plant populations. In addition, wolves often kept animals from grazing in riparian areas, which protected beavers from having their food sources encroached upon. The removal of wolves had a direct effect on beaver populations, as their habitat became territory for grazing. Furthermore, predation keeps hydrological features such as creeks and streams in normal working order. Increased browsing on willows and conifers along Blacktail Creek due to a lack of predation caused channel incision because they helped slow the water down and hold the soil in place.

What changes happened when herbivores were eliminated in Yellowstone?
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A: unanswerable

Problem: At no more than 200 kilometres (120 mi) north to south and 130 kilometres (81 mi) east to west, Swaziland is one of the smallest countries in Africa. Despite its size, however, its climate and topography is diverse, ranging from a cool and mountainous highveld to a hot and dry lowveld. The population is primarily ethnic Swazis whose language is siSwati. They established their kingdom in the mid-18th century under the leadership of Ngwane III; the present boundaries were drawn up in 1881. After the Anglo-Boer War, Swaziland was a British protectorate from 1903 until 1967. It regained its independence on 6 September 1968.
When did the ethnic Swazis establish a kingdom?
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Answer: mid-18th century

Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
Mechanical pulping yields almost a tonne of pulp per tonne of dry wood used, which is why mechanical pulps are sometimes referred to as "high yield" pulps. With almost twice the yield as chemical pulping, mechanical pulps is often cheaper. Mass-market paperback books and newspapers tend to use mechanical papers. Book publishers tend to use acid-free paper, made from fully bleached chemical pulps for hardback and trade paperback books.
What type of pulping yields nearly a tonne of dry wood per pulp tonne used?
A: unanswerable

Context and question: Changes also took place among laymen, as aristocratic culture focused on great feasts held in halls rather than on literary pursuits. Clothing for the elites was richly embellished with jewels and gold. Lords and kings supported entourages of fighters who formed the backbone of the military forces.[I] Family ties within the elites were important, as were the virtues of loyalty, courage, and honour. These ties led to the prevalence of the feud in aristocratic society, examples of which included those related by Gregory of Tours that took place in Merovingian Gaul. Most feuds seem to have ended quickly with the payment of some sort of compensation. Women took part in aristocratic society mainly in their roles as wives and mothers of men, with the role of mother of a ruler being especially prominent in Merovingian Gaul. In Anglo-Saxon society the lack of many child rulers meant a lesser role for women as queen mothers, but this was compensated for by the increased role played by abbesses of monasteries. Only in Italy does it appear that women were always considered under the protection and control of a male relative.
In what society did women have status as abbesses?
Answer: Anglo-Saxon

Question: Philadelphia is home to many national historical sites that relate to the founding of the United States. Independence National Historical Park is the center of these historical landmarks being one of the country's 22 UNESCO World Heritage Sites. Independence Hall, where the Declaration of Independence was signed, and the Liberty Bell are the city's most famous attractions. Other historic sites include homes for Edgar Allan Poe, Betsy Ross, and Thaddeus Kosciuszko, early government buildings like the First and Second Banks of the United States, Fort Mifflin, and the Gloria Dei (Old Swedes') Church. Philadelphia alone has 67 National Historic Landmarks, the third most of any city in the country.
Is there an answer to this question: How many UNESCO sites does the U.S. have?

Answer: 22 UNESCO World Heritage Sites

Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
In separate testimony to Financial Crisis Inquiry Commission, officers of Clayton Holdingsthe largest residential loan due diligence and securitization surveillance company in the United States and Europetestified that Clayton's review of over 900,000 mortgages issued from January 2006 to June 2007 revealed that scarcely 54% of the loans met their originators' underwriting standards. The analysis (conducted on behalf of 23 investment and commercial banks, including 7 "too big to fail" banks) additionally showed that 28% of the sampled loans did not meet the minimal standards of any issuer. Clayton's analysis further showed that 39% of these loans (i.e. those not meeting any issuer's minimal underwriting standards) were subsequently securitized and sold to investors.
How many mortgage loans did Clayton Holdings review in their analysis?
A:
900,000