Question: How many acts is the ballet Rita Sangalli premiered in, in the year 1876?

Context:
Rita Sangalli
Rita Sangalli (20 August 1849 – 3 November 1909) was an Italian ballet dancer.
 Born in Antegnate, she danced in the Italian provinces of Asti, Piacenza, and Turin, making her 1865 debut at Milan's La Scala in Paul Taglioni's (1808-1884) "Flik and Flok", before being hired for the opera at Her Majesty's Theatre in London.
 In 1872, she danced the principal role in "La source" at its successful revival.
 In the same year, she joined the Paris Opera Ballet, where she performed in numerous premieres, including in the role of "Sylvia" (14 June 1876), "Yedda" (1879), and "Namouna" (6 March 1882).
 She retired from the company in 1884.
 Sangalli toured America where she performed in "The Black Crook" and "Flick Flock".
 In August 1901, Sangali and Marie Bonfanti performed at the Metropolitan Opera House, during the inaugural season of ballet at the New York City venue.
 She died in Carpesino d'Arcellasco, Italy.
American Antiquarian Society
The American Antiquarian Society (AAS), located in Worcester, Massachusetts, is both a learned society and national research library of pre-twentieth century American history and culture.
 Founded in 1812, it is the oldest historical society in the United States with a national focus.
 Its main building, known as Antiquarian Hall, is a U.S. National Historic Landmark in recognition of this legacy.
 The mission of the AAS is to collect, preserve and make available for study all printed records of what is now known as the United States of America.
 This includes materials from the first European settlement through the year 1876.
1876 in architecture
The year 1876 in architecture involved some significant architectural events and new buildings.
1876 in Germany
Events in the year 1876 in Germany.
1876 in Wales
This article is about the particular significance of the year 1876 to Wales and its people.
Caspar Erich Schieler
Caspar Erasmus (Erich) Schieler (July 14, 1851 – January 13, 1934) was a German theologian, church historian and priest in the late 19th century and early 20th century.
 According to documents provided by Mainz Cathedral and the Diocesan Seminary, Schieler studied philosophy and theology at the Episcopal Seminary in Mainz (Closed during the Kulturkampf in 1878), receiving the Doctor of Divinity degree.
 Schieler first served as a priest at the age of twenty-five at Mainz, Cathedral ordained under Bishop Wilhelm Emmanuel von Ketteler in the year 1876.
 Due to the Kulturkampf, Schieler was interrogated by the German government and forced to pastor his parish in secret, to avoid further attention.
 While secretly pastoring in Weisskirchen, Schieler began working on his dissertation: "Magister Johannes Nider", for which he received the degree of Doctor of Theology, Magna cum Laude in Wurzburg, Germany in the year 1886.
 Schieler then become the Professor of Moral Theology at Diocesan Seminary of Mainz in Baden-Württemberg.
 After breaking from The Catholic Church and converting to Protestantism, Schieler continued writing books and became a pastor in the Lutheran Church, which later merged into the United Church of Christ, a mainline Protestant Christian denomination, with historical confessional roots in the Reformed, Congregational and Lutheran traditions.
 Schieler served as a Professor of theology and Latin American and German language and literature at the Mission House College, which later became Lakeland University.
 At the request of the Educational Department, Schieler later took up a teaching position at Redfield College, teaching theology in Redfield, South Dakota.
 Schieler was then called upon by the German Evangelical Synod of North America, to teach and preach in communities in Hartsburg, Missouri, Hamel and Johannisburg, Illinois and Marion, Wisconsin.
Education in Sambalpur
Sambalpur is a city in Sambalpur district in the Indian state of Odisha.
 It lies at a distance of 321 km from the state capital Bhubaneswar.
 In the year 1876, Sambalpur was established as a municipality.
 It is currently the headquarters and the largest city of Sambalpur district.
 It is also the commercial capital of Western Odisha.
 Sambalpur is famous for Hirakud Dam, Sambalpuri Saree, Sambalpuri songs, Sambalpuri dance, the Sitalsasthi Carnival, The Leaning Temple of Huma and Gandhi temple.
1876 in Scotland
Events from the year 1876 in Scotland.
Sylvia (ballet)
Sylvia, originally Sylvia, ou La nymphe de Diane, is a full-length ballet in two or three acts, first choreographed by Louis Mérante to music by Léo Delibes in 1876.
 "Sylvia" is a typical classical ballet in many respects, yet it has many interesting features that make it unique.
 "Sylvia" is notable for its mythological Arcadian setting, creative choreographies, expansive sets and, above all, its remarkable score.
Marie Bonfanti
Marie Bonfanti (1845-1921) was a 19th-century ballet dancer whose New York City première came at Niblo's Garden on Monday, September 10, 1866.
 She then was the prima ballerina in "The Black Crook" at the same theatre, which premièred two days later.
 She appeared in "Sylvia" by Léo Delibes at the Metropolitan Alcazar concert hall on July 15, 1882.
 In August 1901, Bonfanti performed with Rita Sangalli at the Metropolitan Opera House, during the inaugural season of ballet at the New York City venue.
 Her talent for expressionist dancing and her private life were covered widely from the mid-1860s until the early 20th century.

Answer: two or three acts