Problem: BeiDou Navigation Satellite System:

The second generation of the system, officially called the BeiDou Navigation Satellite System (BDS) and also known as COMPASS or BeiDou-2, will be a global satellite navigation system consisting of 35 satellites, and is under construction as of January 2015[update]. It became operational in China in December 2011, with 10 satellites in use, and began offering services to customers in the Asia-Pacific region in December 2012. It is planned to begin serving global customers upon its completion in 2020.

Which system is also known as COMPANION or BeiDou-23?
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A: unanswerable

Problem: Traditional Eritrean attire is quite varied among the ethnic groups of Eritrea. In the larger cities, most people dress in Western casual dress such as jeans and shirts. In offices, both men and women often dress in suits. Traditional clothing for Christian Tigrinya-speaking highlanders consists of bright white gowns called zurias for the women, and long white shirts accompanied by white pants for the men. In Muslim communities in the Eritrean lowland, the women traditionally dress in brightly colored clothes. Only Rashaida women maintain a tradition of covering half of their faces, though they do not cover their hair.
What men in Eritrea cover their hair?
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Answer: unanswerable

Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
In the wake of the discovery, there was much nationalistic rivalry between the French and the British over who deserved credit for the discovery. Eventually, an international consensus emerged that both Le Verrier and Adams jointly deserved credit. Since 1966, Dennis Rawlins has questioned the credibility of Adams's claim to co-discovery, and the issue was re-evaluated by historians with the return in 1998 of the "Neptune papers" (historical documents) to the Royal Observatory, Greenwich. After reviewing the documents, they suggest that "Adams does not deserve equal credit with Le Verrier for the discovery of Neptune. That credit belongs only to the person who succeeded both in predicting the planet's place and in convincing astronomers to search for it."
What papers were written in 1998?
A: unanswerable

Context and question: The American bison is a large bovid which inhabited much of western North America prior to the 1800s, living on the prairies in large herds. However, the vast herds of bison attracted market hunters, who killed dozens of bison for their hides only, leaving the rest to rot. Thousands of these hunters quickly eliminated the bison herds, bringing the population from several million in the early 1800s to a few hundred by the 1880s. Conservation efforts have allowed the population to increase, but the bison remains near-threatened.
How much did a bison hide cost in the 1800's?
Answer: unanswerable

Question: The successful outcome of antimicrobial therapy with antibacterial compounds depends on several factors. These include host defense mechanisms, the location of infection, and the pharmacokinetic and pharmacodynamic properties of the antibacterial. A bactericidal activity of antibacterials may depend on the bacterial growth phase, and it often requires ongoing metabolic activity and division of bacterial cells. These findings are based on laboratory studies, and in clinical settings have also been shown to eliminate bacterial infection. Since the activity of antibacterials depends frequently on its concentration, in vitro characterization of antibacterial activity commonly includes the determination of the minimum inhibitory concentration and minimum bactericidal concentration of an antibacterial. To predict clinical outcome, the antimicrobial activity of an antibacterial is usually combined with its pharmacokinetic profile, and several pharmacological parameters are used as markers of drug efficacy.
Is there an answer to this question: What besides ongoing metabolic activity is required in bactericidal activity?

Answer: division of bacterial cells

The capital is Nashville, though Knoxville, Kingston, and Murfreesboro have all served as state capitals in the past. Memphis has the largest population of any city in the state. Nashville's 13-county metropolitan area has been the state's largest since c. 1990. Chattanooga and Knoxville, both in the eastern part of the state near the Great Smoky Mountains, each has approximately one-third of the population of Memphis or Nashville. The city of Clarksville is a fifth significant population center, some 45 miles (72 km) northwest of Nashville. Murfreesboro is the sixth-largest city in Tennessee, consisting of some 108,755 residents.
If it is possible to answer this question, answer it for me (else, reply "unanswerable"): How many counties are part of Nashville's metropolitan area?
Ah, so..
13