Input: Read this: Stepper motors are a type of motor frequently used when precise rotations are required. In a stepper motor an internal rotor containing PMs or a magnetically soft rotor with salient poles is controlled by a set of external magnets that are switched electronically. A stepper motor may also be thought of as a cross between a DC electric motor and a rotary solenoid. As each coil is energized in turn, the rotor aligns itself with the magnetic field produced by the energized field winding. Unlike a synchronous motor, in its application, the stepper motor may not rotate continuously; instead, it "steps"starts and then quickly stops againfrom one position to the next as field windings are energized and de-energized in sequence. Depending on the sequence, the rotor may turn forwards or backwards, and it may change direction, stop, speed up or slow down arbitrarily at any time.
Question: When are stepper motors least useful?

Output: unanswerable

Input: Read this: The most innovative period of Cubism was before 1914. After World War I, with the support given by the dealer Leonce Rosenberg, Cubism returned as a central issue for artists, and continued as such until the mid-1920s when its avant-garde status was rendered questionable by the emergence of geometric abstraction and Surrealism in Paris. Many Cubists, including Picasso, Braque, Gris, Leger, Gleizes, and Metzinger, while developing other styles, returned periodically to Cubism, even well after 1925. Cubism reemerged during the 1920s and the 1930s in the work of the American Stuart Davis and the Englishman Ben Nicholson. In France, however, Cubism experienced a decline beginning in about 1925. Leonce Rosenberg exhibited not only the artists stranded by Kahnweiler's exile but others including Laurens, Lipchitz, Metzinger, Gleizes, Csaky, Herbin and Severini. In 1918 Rosenberg presented a series of Cubist exhibitions at his Galerie de l'Effort Moderne in Paris. Attempts were made by Louis Vauxcelles to claim that Cubism was dead, but these exhibitions, along with a well-organized Cubist show at the 1920 Salon des Independants and a revival of the Salon de la Section d'Or in the same year, demonstrated it was still alive.
Question: Before what year was Cubism considered the least innovative?

Output: unanswerable

Input: Read this: The coastline of Norfolk Island consists, to varying degrees, of cliff faces. A downward slope exists towards Slaughter Bay and Emily Bay, the site of the original colonial settlement of Kingston. There are no safe harbour facilities on Norfolk Island, with loading jetties existing at Kingston and Cascade Bay. All goods not domestically produced are brought in by ship, usually to Cascade Bay. Emily Bay, protected from the Pacific Ocean by a small coral reef, is the only safe area for recreational swimming, although surfing waves can be found at Anson and Ball Bays.
Question: Where can you go to surf on Norfolk Island?

Output: Anson and Ball Bays

Input: Read this: Layer III audio can also use a "bit reservoir", a partially full frame's ability to hold part of the next frame's audio data, allowing temporary changes in effective bitrate, even in a constant bitrate stream. Internal handling of the bit reservoir increases encoding delay.[citation needed]
Question: What kind of audio is required to use a bit reservoir?

Output:
Layer III