Problem: Raleigh, North Carolina:

Several other professional sports leagues have had former franchises (now defunct) in Raleigh, including the Raleigh IceCaps of the ECHL (19911998); Carolina Cobras of the Arena Football League (20002004); the RaleighDurham Skyhawks of the World League of American Football (1991); the Raleigh Bullfrogs of the Global Basketball Association (19911992); the Raleigh Cougars of the United States Basketball League (19971999); and most recently, the Carolina Courage of the Women's United Soccer Association (20002001 in Chapel Hill, 20012003 in suburban Cary), which won that league's championship Founders Cup in 2002.

What team played soccer in Chapel hill in 2004?
---
A: unanswerable

Problem: Tajikistan:

In 2009 Tajikistan had 26 airports, 18 of which had paved runways, of which two had runways longer than 3,000 meters. The country's main airport is Dushanbe International Airport which as of April 2015, had regularly scheduled flights to major cities in Russia, Central Asia, as well as Delhi, Dubai, Frankfurt, Istanbul, Kabul, Tehran, and Urumqi amongst others. There are also international flights, mainly to Russia, from Khujand Airport in the northern part of the country as well as limited international services from Kulob Airport, and Qurghonteppa International Airport. Khorog Airport is a domestic airport and also the only airport in the sparsely populated eastern half of the country.

What is the country's main airport?
---
A: Dushanbe International Airport

Problem: Classical music:

In 19961997, a research study was conducted on a large population of middle age students in the Cherry Creek School District in Denver, Colorado, USA. The study showed that students who actively listen to classical music before studying had higher academic scores. The research further indicated that students who listened to the music prior to an examination also had positively elevated achievement scores. Students who listened to rock-and-roll or country had moderately lower scores. The study further indicated that students who used classical during the course of study had a significant leap in their academic performance; whereas, those who listened to other types of music had significantly lowered academic scores. The research was conducted over several schools within the Cherry Creek School District and was conducted through University of Colorado. This study is reflective of several recent studies (i.e. Mike Manthei and Steve N. Kelly of the University of Nebraska at Omaha; Donald A. Hodges and Debra S. O'Connell of the University of North Carolina at Greensboro; etc.) and others who had significant results through the discourse of their work.

Who experience a significant leap in their academic performance?
---
A: students who used classical during the course of study

Problem: Computer security:

One use of the term "computer security" refers to technology that is used to implement secure operating systems. In the 1980s the United States Department of Defense (DoD) used the "Orange Book" standards, but the current international standard ISO/IEC 15408, "Common Criteria" defines a number of progressively more stringent Evaluation Assurance Levels. Many common operating systems meet the EAL4 standard of being "Methodically Designed, Tested and Reviewed", but the formal verification required for the highest levels means that they are uncommon. An example of an EAL6 ("Semiformally Verified Design and Tested") system is Integrity-178B, which is used in the Airbus A380 and several military jets.

What makes it difficult for systems to use the EAL4 standard?
---
A:
unanswerable