Question: Avignon was the seat of the papacy from 1309 to 1376. With the return of the Pope to Rome in 1378, the Papal State developed into a major secular power, culminating in the morally corrupt papacy of Alexander VI. Florence grew to prominence amongst the Italian city-states through financial business, and the dominant Medici family became important promoters of the Renaissance through their patronage of the arts. Other city states in northern Italy also expanded their territories and consolidated their power, primarily Milan and Venice. The War of the Sicilian Vespers had by the early 14th century divided southern Italy into an Aragon Kingdom of Sicily and an Anjou Kingdom of Naples. In 1442, the two kingdoms were effectively united under Aragonese control.
Is there an answer to this question: In what year didn't the papacy return to Rome?

Answer: unanswerable

Question: While highly effective, the requirement for injection limited the use of norepinephrine[clarification needed] and orally active derivatives were sought. A structurally similar compound, ephedrine, was identified by Japanese chemists in the Ma Huang plant and marketed by Eli Lilly as an oral treatment for asthma. Following the work of Henry Dale and George Barger at Burroughs-Wellcome, academic chemist Gordon Alles synthesized amphetamine and tested it in asthma patients in 1929. The drug proved to have only modest anti-asthma effects, but produced sensations of exhilaration and palpitations. Amphetamine was developed by Smith, Kline and French as a nasal decongestant under the trade name Benzedrine Inhaler. Amphetamine was eventually developed for the treatment of narcolepsy, post-encepheletic parkinsonism, and mood elevation in depression and other psychiatric indications. It received approval as a New and Nonofficial Remedy from the American Medical Association for these uses in 1937 and remained in common use for depression until the development of tricyclic antidepressants in the 1960s.
Is there an answer to this question: What were some uses for the American Medical Association?

Answer: unanswerable

Question: The essence of air defence is to detect hostile aircraft and destroy them. The critical issue is to hit a target moving in three-dimensional space; an attack must not only match these three coordinates, but must do so at the time the target is at that position. This means that projectiles either have to be guided to hit the target, or aimed at the predicted position of the target at the time the projectile reaches it, taking into account speed and direction of both the target and the projectile.
Is there an answer to this question: What is the first purpose of air defence?

Answer: detect hostile aircraft

Question: The 19th century also saw the use of red in art to create specific emotions, not just to imitate nature. It saw the systematic study of color theory, and particularly the study of how complementary colors such as red and green reinforced each other when they were placed next to each other. These studies were avidly followed by artists such as Vincent van Gogh. Describing his painting, The Night Cafe, to his brother Theo in 1888, Van Gogh wrote: "I sought to express with red and green the terrible human passions. The hall is blood red and pale yellow, with a green billiard table in the center, and four lamps of lemon yellow, with rays of orange and green. Everywhere it is a battle and antithesis of the most different reds and greens."
Is there an answer to this question: What was the name of vincent van Gogh's brother?

Answer:
Theo