In this task you will be given a text passage from a trivia quiz. You should choose the category this question belongs to from these categories: History, Science, Social Science, Fine Arts, Literature. You can only choose one category, so if in doubt, please choose the closest match.
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Question: Notably, one of these entities is absent in the Leishmania mexicana GPI8 protein, and abnormally low numbers of pericytes occur if one is missing from PDGF. Binding of 14-3-3 proteins to GABAB ["Gabba-sub-bee"] receptors does not occur when two arginines are mutated to alanine in one of these entities, which also binds to the COPI complex. They are usually C-terminal signals, and a common mammalian one consists of the amino acids lysine, aspartate, gluatamate, and leucine, or KDEL. hnRNP C proteins contain one of them that allows them to override nuclear export signals. For 10 points, name these signals important in directing proteins to the correct membranes, most often used to prevent a protein's export from the endoplasmic reticulum. 

Answer: Science


Question: Several of his early works, including such operas as Cleonice, Demofoonte, and Artaserse, were written with librettist Pietro Metastasio. He had begun composing an opera based on the Song of Roland, but the discovery that Niccolo Piccini was given the same libretto to work on sparked a rivalry in the Parisian press and motivated him to compose Armide. Collaboration with the librettist Calzabigi resulted in the composition of the ballets Semiramide and Don Juan, as well as an opera featuring the "Dance of the Blessed Spirits" and another in whose preface he declared his intent to "restrict music to its true office of serving poetry. " FTP, identify this German classical composer of "reform" operas such as Alceste and Orfeo et Euridice.

Answer: Fine Arts


Question: This city has a six hundred year old Orloj, or astronomical clock, on its Old Town City Hall. The Ginger Rogers and Fred Astaire-inspired Dancing House was built in this city by architect Frank Gehry. A bridge in this city with 30 statues along its sides was started in 1357 and became known as the Charles Bridge. That bridge crosses the Vltava River (VOL-tah-vah) in this city. For 10 points, name this city in Eastern Europe that is both the largest in and the capital city of the Czech Republic.

Answer:
Social Science