Background: Thor Heyerdahl (Norwegian pronunciation: [tu:r 'haei@da:l]; October 6, 1914 - April 18, 2002) was a Norwegian adventurer and ethnographer with a background in zoology, botany, and geography. He became notable for his Kon-Tiki expedition in 1947, in which he sailed 8,000 km (5,000 mi) across the Pacific Ocean in a hand-built raft from South America to the Tuamotu Islands. The expedition was designed to demonstrate that ancient people could have made long sea voyages, creating contacts between separate cultures. This was linked to a diffusionist model of cultural development.
Context: In 1947, Heyerdahl and five fellow adventurers sailed from Peru to the Tuamotu Islands, French Polynesia in a pae-pae raft that they had constructed from balsa wood and other native materials, christened the Kon-Tiki. The Kon-Tiki expedition was inspired by old reports and drawings made by the Spanish Conquistadors of Inca rafts, and by native legends and archaeological evidence suggesting contact between South America and Polynesia. The Kon-Tiki smashed into the reef at Raroia in the Tuamotus on August 7, 1947, after a 101-day, 4,300-nautical-mile (5,000-mile or 8,000 km) journey across the Pacific Ocean. Heyerdahl had nearly drowned at least twice in childhood and did not take easily to water; he said later that there were times in each of his raft voyages when he feared for his life. Kon-Tiki demonstrated that it was possible for a primitive raft to sail the Pacific with relative ease and safety, especially to the west (with the trade winds). The raft proved to be highly manoeuvrable, and fish congregated between the nine balsa logs in such numbers that ancient sailors could have possibly relied on fish for hydration in the absence of other sources of fresh water. Other rafts have repeated the voyage, inspired by Kon-Tiki. Heyerdahl's book about The Kon-Tiki Expedition: By Raft Across the South Seas has been translated into 70 languages. The documentary film of the expedition entitled Kon-Tiki won an Academy Award in 1951. A dramatised version was released in 2012, also called Kon-Tiki, and was nominated for both the Best Foreign Language Oscar at the 85th Academy Awards and a Golden Globe Award for Best Foreign Language Film at the 70th Golden Globe Awards. It was the first time that a Norwegian film was nominated for both an Oscar and a Golden Globe. Anthropologists continue to believe that Polynesia was settled from west to east, based on linguistic, physical, and genetic evidence, migration having begun from the Asian mainland. There are controversial indications, though, of some sort of South American/Polynesian contact, most notably in the fact that the South American sweet potato is served as a dietary staple throughout much of Polynesia. Blood samples taken in 1971 and 2008 from Easter Islanders without any European or other external descent were analysed in a 2011 study, which concluded that the evidence supported some aspects of Heyerdahl's hypothesis. This result has been questioned because of the possibility of contamination by South Americans after European contact with the islands. However, more recent DNA work (after Heyerdahl's death) contradicts the post-European-contact contamination hypothesis, finding the South American DNA sequences to be far older than that. Heyerdahl had attempted to counter the linguistic argument with the analogy that he would prefer to believe that African-Americans came from Africa, judging from their skin colour, and not from England, judging from their speech.
Question: How long did they stay once they arrived there?
Answer:

Problem: Background: Winfrey's first name was spelled "Orpah" on her birth certificate after the biblical figure in the Book of Ruth, but people mispronounced it regularly and "Oprah" stuck. She was born in Kosciusko, Mississippi, to an unmarried teenage mother. She later said that her conception was due to a single sexual encounter and the couple broke up not long after. Her mother, Vernita Lee (born c. 1935), was a housemaid.
Context: In 1993, Winfrey hosted a rare prime-time interview with Michael Jackson, which became the fourth most-watched event in American television history as well as the most watched interview ever, with an audience of 36.5 million. On December 1, 2005, Winfrey appeared on the Late Show with David Letterman to promote the new Broadway musical The Color Purple, of which she was a producer, joining the host for the first time in 16 years. The episode was hailed by some as the "television event of the decade" and helped Letterman attract his largest audience in more than 11 years: 13.45 million viewers. Although a much-rumored feud was said to have been the cause of the rift, both Winfrey and Letterman balked at such talk. "I want you to know, it's really over, whatever you thought was happening", said Winfrey. On September 10, 2007, Letterman made his first appearance on The Oprah Winfrey Show, as its season premiere was filmed in New York City. In 2006, rappers Ludacris, 50 Cent and Ice Cube criticized Winfrey for what they perceived as an anti-hip hop bias. In an interview with GQ magazine, Ludacris said that Winfrey gave him a "hard time" about his lyrics, and edited comments he made during an appearance on her show with the cast of the film Crash. He also said that he wasn't initially invited on the show with the rest of the cast. Winfrey responded by saying that she is opposed to rap lyrics that "marginalize women", but enjoys some artists, including Kanye West, who appeared on her show. She said she spoke with Ludacris backstage after his appearance to explain her position and said she understood that his music was for entertainment purposes, but that some of his listeners might take it literally. In September 2008, Winfrey received criticism after Matt Drudge of the Drudge Report reported that Winfrey refused to have Sarah Palin on her show, allegedly because of Winfrey's support for Barack Obama. Winfrey denied the report, maintaining that there never was a discussion regarding Palin's appearing on her show. She said that after she made public her support for Obama, she decided that she would not let her show be used as a platform for any of the candidates. Although Obama appeared twice on her show, those appearances were prior to his declaring himself a candidate. Winfrey added that Palin would make a fantastic guest and that she would love to have her on the show after the election, which she did on November 18, 2009. In 2009, Winfrey was criticized for allowing actress Suzanne Somers to appear on her show to discuss hormone treatments that are not accepted by mainstream medicine. Critics have also suggested that Winfrey is not tough enough when questioning celebrity guests or politicians whom she appears to like. Lisa de Moraes, a media columnist for The Washington Post, stated: "Oprah doesn't do follow-up questions unless you're an author who's embarrassed her by fabricating portions of a supposed memoir she's plugged for her book club."
Question: Did she appear on his show more then once?
Answer:
On September 10, 2007, Letterman made his first appearance on The Oprah Winfrey Show, as its season premiere was filmed in New York City.