TASK DEFINITION: In this task, you are given a question and a context passage. You have to answer the question based on the given passage.
PROBLEM: What does the S in "PBS" stand for?, Context: New York is also a major center for non-commercial educational media. The oldest public-access television channel in the United States is the Manhattan Neighborhood Network, founded in 1971. WNET is the city's major public television station and a primary source of national Public Broadcasting Service (PBS) television programming. WNYC, a public radio station owned by the city until 1997, has the largest public radio audience in the United States.

SOLUTION: Service

PROBLEM: the above mentioned people are?, Context: Artists contributing to this format include mainly soft rock/pop singers such as, Andy Williams, Johnny Mathis, Nana Mouskouri, Celine Dion, Julio Iglesias, Frank Sinatra, Barry Manilow, Engelbert Humperdinck, and Marc Anthony.

SOLUTION: Artists

PROBLEM: What was invented after de Rivaz engine?, Context: Hydrogen was liquefied for the first time by James Dewar in 1898 by using regenerative cooling and his invention, the vacuum flask. He produced solid hydrogen the next year. Deuterium was discovered in December 1931 by Harold Urey, and tritium was prepared in 1934 by Ernest Rutherford, Mark Oliphant, and Paul Harteck. Heavy water, which consists of deuterium in the place of regular hydrogen, was discovered by Urey's group in 1932. François Isaac de Rivaz built the first de Rivaz engine, an internal combustion engine powered by a mixture of hydrogen and oxygen in 1806. Edward Daniel Clarke invented the hydrogen gas blowpipe in 1819. The Döbereiner's lamp and limelight were invented in 1823.

SOLUTION:
hydrogen gas blowpipe