Context and question: In comparison to the principal alternative, the diesel engine, electric railways offer substantially better energy efficiency, lower emissions and lower operating costs. Electric locomotives are usually quieter, more powerful, and more responsive and reliable than diesels. They have no local emissions, an important advantage in tunnels and urban areas. Some electric traction systems provide regenerative braking that turns the train's kinetic energy back into electricity and returns it to the supply system to be used by other trains or the general utility grid. While diesel locomotives burn petroleum, electricity is generated from diverse sources including many that do not produce carbon dioxide such as nuclear power and renewable forms including hydroelectric, geothermal, wind and solar.
Which locomotives have no global emissions?
Answer: unanswerable
Context and question: The Times and The Sunday Times have had an online presence since March 1999, originally at the-times.co.uk and sunday-times.co.uk, and later at timesonline.co.uk. There are now two websites: thetimes.co.uk is aimed at daily readers, and the thesundaytimes.co.uk site at providing weekly magazine-like content. There are also iPad and Android editions of both newspapers. Since July 2010, News UK has required readers who do not subscribe to the print edition to pay 2 per week to read The Times and The Sunday Times online.
The website, thetimes.co.uk, is aimed at what kind of reader?
Answer: daily readers
Context and question: Proto-Slavic, the supposed ancestor language of all Slavic languages, is a descendant of common Proto-Indo-European, via a Balto-Slavic stage in which it developed numerous lexical and morphophonological isoglosses with the Baltic languages. In the framework of the Kurgan hypothesis, "the Indo-Europeans who remained after the migrations [from the steppe] became speakers of Balto-Slavic".
What proposes the Indo-Europeans that migrated became speakers of Balto-Slavic?
Answer:
unanswerable