IN: Rowan & Martin's Laugh-In (often simply referred to as Laugh-In) is an American sketch comedy television program that ran for 140 episodes from January 22, 1968, to March 12, 1973, on the NBC television network. It was hosted by comedians Dan Rowan and Dick Martin. Laugh-In originally aired as a one-time special on September 9, 1967, and was such a success that it was brought back as a series, replacing The Man from U.N.C.L.E. on Mondays at 8 pm (ET). The title of the show was a play on the "love-ins" or "be-ins" of the 1960s hippie culture, terms that were, in turn, derived from "sit-ins", common in protests associated with civil rights and antiwar demonstrations of the time.

The 1970-71 season brought new additions to the cast include tall, lanky, sad-eyed Dennis Allen, who alternately played quietly zany characters and straight man for anybody's jokes; comic actress Ann Elder, who also contributed to scripts, tap dancer Barbara Sharma, and Johnny Brown.  Arte Johnson, who created many memorable characters, insisted on star billing, apart from the rest of the cast. The producer mollified him, but had announcer Gary Owens read Johnson's credit as a separate sentence: "Starring Dan Rowan and Dick Martin! And Arte Johnson! With Ruth Buzzi ..." This maneuver gave Johnson star billing, but made it sound like he was still part of the ensemble cast. Johnson left the show after the 1970-71 season. Henry Gibson also departed after the 1970-71 season. Johnson and he were replaced by former Hogan's Heroes stars Richard Dawson and Larry Hovis, both of whom had appeared occasionally in the first season. However, the loss of Johnson's many popular characters caused ratings to drop further.  After winning the Academy Award for Best Supporting Actress in Cactus Flower, Goldie Hawn made a guest appearance in the third episode of the fourth season. She began the episode as an arrogant snob of an actress; however, a bucket of water thrown at her transformed her back to her giggling dumb blonde persona.  The show celebrated its 100th episode during the 1971-72 season, with Carne, Worley, Johnson, Gibson, Graves, and Tiny Tim all returning for the festivities. John Wayne was on hand for his first cameo appearance since 1968.

Did anyone else leave?

OUT: Johnson and he were replaced by former Hogan's Heroes stars Richard Dawson and Larry Hovis,

input: Tu Youyou carried on her work in the 1960s and 70s during China's Cultural Revolution, when scientists were denigrated as one of the nine black categories in society according to Maoist theory (or possibly that of the Gang of Four).  In 1967, during the Vietnam War, Ho Chi Minh, the leader of North Vietnam, which was at war against South Vietnam and the United States, asked Chinese Premier Zhou Enlai for help in developing a malaria treatment for his soldiers trooping down the Ho Chi Minh trail, where a majority came down with a form of malaria which is resistant to chloroquine. Because malaria was also a major cause of death in China's southern provinces including Hainan, Yunnan, Guangxi, and Guangdong, Zhou Enlai convinced Mao Zedong to set up a secret drug discovery project, named Project 523 after its starting date, 23 May 1967. Upon joining the project unit, Tu was initially sent to Hainan where she studied patients who had been infected with the disease. During the time she spent there, her husband was banished to the countryside, meaning that her daughter had to be entrusted to a nursery in Beijing.  Scientists worldwide had screened over 240,000 compounds without success. In 1969, Tu Youyou, then 39 years old, had an idea of screening Chinese herbs. She first investigated the Chinese medical classics in history, visiting practitioners of traditional Chinese medicine all over the country on her own. She gathered her findings in a notebook called A Collection of Single Practical Prescriptions for Anti-Malaria. Her notebook summarized 640 prescriptions. Her team also screened over 2,000 traditional Chinese recipes and made 380 herbal extracts, which were tested on mice.  One compound was effective, sweet wormwood (Artemisia annua), which was used for "intermittent fevers," a hallmark of malaria. As Tu also presented at the project seminar, its preparation was described in a 1,600-year-old text, in a recipe titled, "Emergency Prescriptions Kept Up One's Sleeve". At first, it didn't work, because they extracted it with traditional boiling water. Tu Youyou discovered that a low-temperature extraction process could be used to isolate an effective antimalarial substance from the plant; Tu says she was influenced by a traditional Chinese herbal medicine source, The Handbook of Prescriptions for Emergency Treatments, written in 340 by Ge Hong, which states that this herb should be steeped in cold water. This book contained the useful reference to the herb: "A handful of qinghao immersed with two litres of water, wring out the juice and drink it all." After rereading the recipe, Tu realised the hot water had already damaged the active ingredient in the plant; therefore she proposed a method using low-temperature ether to extract the effective compound instead. The animal tests showed it was completely effective in mice and monkeys.  Furthermore, Tu volunteered to be the first human subject. "As head of this research group, I had the responsibility" she said. It was safe, so she conducted successful clinical trials with human patients. Her work was published anonymously in 1977. In 1981, she presented the findings relating to artemisinin at a meeting with the World Health Organization.

Answer this question "did she use the sweet wormwood to treat Malaria?"
output:
Tu Youyou discovered that a low-temperature extraction process could be used to isolate an effective antimalarial substance from the plant;