instruction:
In this task, you're expected to write answers to questions involving multiple references to the same entity. The answer to the question should be unambiguous and a phrase in the paragraph. Most questions can have only one correct answer.
question:
Passage: Dr. Frank Peralta is stabbed to death in his apartment one night. The detective on the case, Lt. Stevenson, quickly finds multiple witnesses putting Peralta's lover, Terry Collins, at the scene. However, when Stevenson finds Terry and questions her, she has an iron-clad alibi with multiple witnesses. It is revealed that Terry has an identical twin sister, Ruth, and the pair share the same job and routinely switch places for their own benefit. Stevenson and the district attorney are unable to prosecute, since the twins refuse to confirm which one of them has the alibi.
Unable to accept the "perfect crime", Lt. Stevenson asks Dr. Scott Elliot for help. Scott is an expert on twin study, and has been routinely encountering the Collins twins at their shared place of work, but does not know which one is which. As a front, Scott asks Terry and Ruth if he can study both of them individually as part of his research. The twins accept, though Ruth is worried that Scott might find out that Terry was at Peralta's apartment the night of the murder. However, Terry is attracted to Scott and insists that they can keep the secret for the sake of seeing him. She also comforts Ruth, reminding her that she was only at Peralta's apartment but didn't kill him.
From Scott's psychological tests and by spending time with them, he discovers that Ruth is kind and loving, while Terry is highly intelligent, insane, and has been manipulating Ruth almost their entire lives. Terry is jealous that people keep preferring Ruth over her, and is again enraged when Scott falls in love with Ruth instead of her. Terry starts methodically gaslighting Ruth, making her believe that she's hallucinating and going insane, in the hopes of pushing her to suicide.
Question: What is the last name of the person whose murder the insane woman is suspected of committing?
answer:
Peralta.

question:
Passage: On Christmas Eve in 19th-century London, Fred is sliding on ice on a sidewalk. He meets Peter and Tim Cratchit, sons of his uncle Ebenezer's clerk, Bob Cratchit. When Fred reveals who he is, the boys take off in terror. Fred soon arrives at the counting-house of his miserly maternal uncle, Ebenezer Scrooge. After declining an invitation from his nephew to dine with him on Christmas, Scrooge rejects two gentlemen collecting money for charity. That night, Scrooge reluctantly allows his employee Bob Cratchit to have Christmas off with pay but orders him back all the earlier the day after. Later Bob accidentally knocks off Scrooge's hat with a snowball. Scrooge dismisses Bob and withholds a week's pay to compensate for his ruined hat, also demanding a shilling to make up the difference. Bob spends the last of his wages on food for his family's Christmas dinner.
In his house, Scrooge is confronted by the ghost of his deceased business partner, Jacob Marley, who warns Scrooge to repent his wicked ways or he will be condemned in the afterlife as Marley was. He tells Scrooge he will be haunted by three spirits.
At one o'clock, Scrooge is visited by the youthful Ghost of Christmas Past, who takes him back in time to his early life. Scrooge is shown his unhappiness when he was left to spend the holidays alone at school, and his joy when his sister, Fran, came to take him home for Christmas. The spirit reminds Scrooge that Fran, dead for some years, is the mother of his nephew. Scrooge is shown his early career in business and money lending as an employee under Fezziwig.
Question: Who explains that there will be three spirits?
answer:
Jacob Marley.

question:
Passage: William Etty was born in 1787, the son of a York baker and miller. He began as an apprentice printer in Hull. On completing his seven-year apprenticeship he moved at the age of 18 to London "with a few pieces of chalk crayons", with the intention of becoming a history painter in the tradition of the Old Masters. He enrolled at the Royal Academy, and after a year spent studying under renowned portrait painter Thomas Lawrence, Etty returned to the Royal Academy, drawing at the life class and copying other paintings. A follower of John Opie, who promoted the unfashionable painting style of Titian and Rubens over the then-prevalent formal style of Joshua Reynolds, Etty was unsuccessful in all the Academy's competitions and every work he submitted to the Royal Academy Summer Exhibition in the 1810s was rejected. In 1821 the Royal Academy accepted and exhibited one of Etty's works in the Summer Exhibition, The Arrival of Cleopatra in Cilicia (also known as The Triumph of Cleopatra). This painting was extremely well received, and many of Etty's fellow artists greatly admired him. He became well respected for his ability to capture flesh tones accurately in painting, and for his fascination with contrasts in skin tones. Following the exhibition of Cleopatra, over the next decade Etty tried to replicate its success by painting nude figures in biblical, literary and mythological settings.While some nudes by foreign artists were held in private English collections, the country had no tradition of nude painting and the display and distribution of nude material to the public had been suppressed since the 1787 Proclamation for the Discouragement of Vice. Etty was the first British artist to specialise in the nude, and the reaction of the lower classes to these paintings caused concern throughout the 19th century. Many critics condemned his repeated depictions of female nudity as indecent, although his portraits of male nudes were generally well received.
Question: What is the last name of the person who enrolled at the Royal Academy?
answer:
Etty.