题目

(本小题满分12分) 已知集合A＝{x|x2－2x－8≤0，x∈R}，B＝{x|x2－(2m－3)x＋m2－3m≤0，x∈R，m∈R}． (1)若A∩B＝[2,4]，求实数m的值； (2)设全集为R，若A∁RB，求实数m的取值范围． 答案：由已知得A＝[－2,4]，B＝[m－3，m]． (1)∵A∩B＝[2,4]， ∴m－3＝2，且m≥4.∴m＝5. (2)∵B＝[m－3，m]， ∴∁RB＝(－∞，m－3)∪(m，＋∞)． ∵A∁RB，∴m－3>4或m<－2. ∴m>7或m<－2. ∴m∈(－∞，－2)∪(7，＋∞)．Oprah Winfrey, the queen of American daytime talk TV, is considered one of the most powerful women in the world. Now, after 25 years’ hosting The Oprah Winfrey Show, the star has announced she is calling it quits.According to the Los Angeles Times, the move “signals the beginning of the decline for the daytime talk show.” More women are working full-time jobs, and people are turning to cable (有线电视) and pre-recorded shows for their entertainment.It may be that Oprah isn’t quitting so much as moving on. She has created the Oprah Winfrey Network (OWN), and will most likely move her show to the network. If audiences around the world need Oprah, they well know where to look.Oprah Winfrey was born to a single teenage mother in a small town in rural Mississippi, US. As a child, she lived with poverty and abuse. But she got a job at a local radio station, where her honesty, emotional style won her many fans. She quickly rose through the ranks of radio and television before launching her own production company and starting her own show.Oprah’s talk show was not the first of its kind, but it quickly became the best and most popular. It made talk shows popular, and others jumped in to start similar shows. But while other talk shows turned ugly, featuring guests who argued and attacked each other with chairs, Oprah rose above the mess.“Part of her power lies in the fact that her life story resonates (产生共鸣) with her audience, as a kind of version of the American dream,” writes Kevin Connolly, a reporter with the BBC.She became a star because of the way she opened up about her problems to her audience. She shared her own struggles with relationships and weight. She focused on self-help. Connolly believes “something in her honesty and her sometimes painfully emotional directness struck home with a certain type of American”.60. Which of the following statements is NOT true? A. The stop of Oprah’s show reflects the decrease of audience. B. Oprah hosted her showfor about 25 years. C. American talk show was pioneered by Oprah. D. Oprah used to be a radio presenter.61. What does the underlined sentence mean?A. Oprah could deal with the guests fighting very well. B. Oprah’s show stood out with her unique style. C. Oprah turned a deaf ear to other people’s quarrel. D. Oprah’s fame rose because lots of people watch her show.62. From Kevin Connolly, we know people like Oprah’s show for all the reasons EXCEPT ________. A. Oprah always shares people’s life stories in her show B. the audiences are touched by Oprah’s honesty and frankness C. Oprah’s life story reflects the truth of American dream D. some audiences are inspired by Oprah’s show63. According to the text, Oprah ________. A. always volunteers to help those who need help B. has practiced presentational skills since she was young C. believes that one should rely on himself to solve problemsD. calls on women to work full-time jobs