Context and question: Numerous modern mandolin makers build instruments that largely replicate the Gibson F-5 Artist models built in the early 1920s under the supervision of Gibson acoustician Lloyd Loar. Original Loar-signed instruments are sought after and extremely valuable. Other makers from the Loar period and earlier include Lyon and Healy, Vega and Larson Brothers. Some notable modern American carved mandolin manufacturers include, in addition to Kay, Gibson, Weber, Monteleone and Collings. Mandolins from other countries include The Loar (China), Santa, Rosa (China), Michael Kelly (Korea), Eastman (China), Kentucky (China), Heiden (Canada), Gilchrist (Australia) and Morgan Monroe (China).
When was the Gibson F-5 never replicated?
Answer: unanswerable
Context and question: In the Roman Church, universal positive ecclesiastical laws, based upon either immutable divine and natural law, or changeable circumstantial and merely positive law, derive formal authority and promulgation from the office of pope, who as Supreme Pontiff possesses the totality of legislative, executive, and judicial power in his person. The actual subject material of the canons is not just doctrinal or moral in nature, but all-encompassing of the human condition.
What is the pope's official title?
Answer: Supreme Pontiff
Context and question: The first attempts to use standard-frequency single-phase AC were made in Hungary as far back as 1923, by the Hungarian Kálmán Kandó on the line between Budapest-Nyugati and Alag, using 16 kV at 50 Hz. The locomotives carried a four-pole rotating phase converter feeding a single traction motor of the polyphase induction type at 600 to 1,100 V. The number of poles on the 2,500 hp motor could be changed using slip rings to run at one of four synchronous speeds. The tests were a success so, from 1932 until the 1960s, trains on the Budapest-Hegyeshalom line (towards Vienna) regularly used the same system. A few decades after the Second World War, the 16 kV was changed to the Russian and later French 25 kV system.
The first attempt to use standard-frequency double-phase AC were made in what country? 
Answer:
unanswerable