Context and question: Jethro Burns, best known as half of the comedy duo Homer and Jethro, was also the first important jazz mandolinist. Tiny Moore popularized the mandolin in Western swing music. He initially played an 8-string Gibson but switched after 1952 to a 5-string solidbody electric instrument built by Paul Bigsby. Modern players David Grisman, Sam Bush, and Mike Marshall, among others, have worked since the early 1970s to demonstrate the mandolin's versatility for all styles of music. Chris Thile of California is a well-known player, and has accomplished many feats of traditional bluegrass, classical, contemporary pop and rock; the band Nickel Creek featured his playing in its blend of traditional and pop styles, and he now plays in his band Punch Brothers. Most commonly associated with bluegrass, mandolin has been used a lot in country music over the years. Some well-known players include Marty Stuart, Vince Gill, and Ricky Skaggs.
What type of music did Jethro Burns play? 
Answer: jazz mandolinist
Context and question: Namibia has free education for both Primary and secondary education levels. Grades 1–7 are primary level, grades 8–12 secondary. In 1998, there were 400,325 Namibian students in primary school and 115,237 students in secondary schools. The pupil-teacher ratio in 1999 was estimated at 32:1, with about 8% of the GDP being spent on education. Curriculum development, educational research, and professional development of teachers is centrally organised by the National Institute for Educational Development (NIED) in Okahandja.
How many teachers are there in Namibia in primary and secondary schools?
Answer: unanswerable
Context and question: Treaties may be seen as 'self-executing', in that merely becoming a party puts the treaty and all of its obligations in action. Other treaties may be non-self-executing and require 'implementing legislation'—a change in the domestic law of a state party that will direct or enable it to fulfill treaty obligations. An example of a treaty requiring such legislation would be one mandating local prosecution by a party for particular crimes.
Signing a self-executing treaty automatically does what for a party?
Answer:
puts the treaty and all of its obligations in action