Problem: Railway electrification system:

The first attempts to use standard-frequency single-phase AC were made in Hungary as far back as 1923, by the Hungarian Kalman Kando 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 year?
---
A: unanswerable

Problem: Spectre (2015 film):

To promote the film, production continued the trend established during Skyfall's production of releasing still images of clapperboards and video blogs on Eon's official social media accounts.

What other Bond film was promoted on social media?
---
A: Skyfall

Problem: Ann Arbor, Michigan:

Ann Arbor was founded in 1824 by land speculators John Allen and Elisha Walker Rumsey. On 25 May 1824, the town plat was registered with Wayne County as "Annarbour;" this represents the earliest known use of the town's name. Allen and Rumsey decided to name it for their wives, both named Ann, and for the stands of Bur Oak in the 640 acres (260 ha) of land they purchased for $800 from the federal government at $1.25 per acre. The local Ojibwa named the settlement kaw-goosh-kaw-nick, after the sound of Allen's sawmill.

How much did the founder's wives pay for the settlement?
---
A: unanswerable

Problem: Airport:

At all airports the use of a traffic pattern (often called a traffic circuit outside the U.S.) is possible. They may help to assure smooth traffic flow between departing and arriving aircraft. There is no technical need within modern aviation for performing this pattern, provided there is no queue. And due to the so-called SLOT-times, the overall traffic planning tend to assure landing queues are avoided. If for instance an aircraft approaches runway 17 (which has a heading of approx. 170 degrees) from the north (coming from 360/0 degrees heading towards 180 degrees), the aircraft will land as fast as possible by just turning 10 degrees and follow the glidepath, without orbit the runway for visual reasons, whenever this is possible. For smaller piston engined airplanes at smaller airfields without ILS equipment, things are very differently though.

What is it like for aircraft landing at small airfields as fast as possible while following the glidepath?
---
A:
unanswerable