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.
--------
Question: A maximum independent set for this data structure can be found in linear time by adding alternating levels. In this structure, any two vertices or nodes must be connected by a single simple path, and thus it is connected and acyclic. By using (*) union-find with disjoint sets, one type of this structure containing all the vertices of a connected graph can be constructed. One variety of this data structure can be used to easily implement a binary search. This structure also comes in red-black and self-balancing-binary varieties. For 10 points, identify this data structure from computer science, a hierarchical graph in which "leaf" nodes ultimately flow from a "root" node.

Answer: Science


Question: When he died of a ruptured appendix in 1925, he was only 43, but he had already achieved great acclaim. In fact, he was memorialized by the Metropolitan Museum of Art less than a year after his death. A devotee of Robert Henri, he was noted for his dramatic interpretations of common life, especially in New York City, where he helped organize the Armory Show of 1913. FTP name the painter of Forty-Two Kids, Matinicus, and such prize-fighting scenes as Stag at Sharkey's.		

Answer: Fine Arts


Question: In a paper promoting the TIP5P model of this compound, Mahoney and Jorgensen noted that incorporating terms for flexibility or polarizability does not improve accuracy in modeling its major density anomaly. One of the earliest five-site models of this substance is named for Ben-Naim and Stillinger, and four-site models of this substance place its center of negative charge on a dummy atom and began with the Bernal-Fowler model. Ether is guaranteed free of this compound, when bottled with three or four angstrom molecular sieves, and this compound is removed from reaction mixtures using magnesium and sodium sulfate. This compound reacts with Grignard reagents to give alkanes and forms an azeotrope that is commonly entrained using benzene with ethanol. Such computational models all must take into account its unusually strong hydrogen bonding, which drives up its boiling point to one hundred degrees Celsius. For 10 points, name this compound whose triple point defines the Kelvin scale.

Answer:
Science