请阅读Passage l。完成第21—25小题。 Passage 1 Unless you spend much time sitting in a college classroom or browsing through certain areas of the Internet， it's possible that you had not heard of trigger warnings until a few weeks ago， when they made an appearance in the Times. The newspaper explained that the term refers to preemptive alerts， issued by a professor or an institution at the request of students， indicating that material presented in class might be sufficiently graphic to spark symptoms of post-traumatic-stress disorder. The term seems to have originated in online feminist forums， where trigger warnings have for some years been used to flag discussions of rape or other sexual violence. The Times piece， which was skeptically titled 'Warning: The Literary Canon Could Make Students Squirm，' suggested that trigger warnings are moving from the online fringes to the classroom， and might be more broadly applied to highlight in advance the distress or offense that a work of literature might cause. 'Huckleberry Finn' would come with a warning for those who have experienced racism; 'The Merchant of Venice' would have an anti-Semitism warning attached. The call from students for trigger warnings was spreading on campuses such as Oberlin， where a proposal was drafted that would advise professors to'be aware of racism， classism， sexism， and other issues of privilege and oppression' in devising their syllabi; and Rutgers， where a student argued in the campus newspaper that trigger warnings would contribute to preserving the classroom as a'safe space' for students. Online discussion of trigger warnings has sometimes been guardedly sympathetic， sometimes critical. Jessica Valenti has noted on The Nation's website that potential triggers for trauma are so manifold as to be beyond the possibility of cataloguing : 'There is no trigger warning for living your life.' Some have suggested that a professor's ability to teach would be compromised should it become commonplace for'The Great Gatsby' to bear a trigger warning alerting readers to the disgusting characters and incidents within its pages. Others have worried that trigger-warning advocates， in seeking to protect the vulnerable， run the risk of disempowering them instead. 'Bending the world to accommodate our personal frailties does not help us overcome them'， Jenny Jarvie wrote on The New Republic's online site. Jarvie's piece， like many others on the subject， cited the University of California， Santa Barbara， as a campus where champions of trigger warnings have made significant progress. Earlier this year， students at U.C.S.B. agreed upon a resolution recommending that such warnings be issued in instances where classroom materials might touch upon 'rape， sexual assault， abuse， self-injurious behavior， suicide， and graphic violence'. The resolution was brought by a literature student who said that， as a past victim of sexual violence， she had been shocked when a teacher showed a movie in class which depicted rape， without giving advance notice of the content. The student hoped to spare others the possibility of experiencing a post-traumatic-stress reaction. The trigger-warning debate may， by comparison， seem hard to understand; but express a larger cultural preoccupation with achieving safety， and a fear of living in its absence. The hope that safety might be found， as in a therapist's office， in a classroom where literature is being taught is in direct contradiction to one purpose of literature， which is to give expression through art to difficultanduncomfortableideas，andtherebytoenlargethereader'sexperienceand comprehension. The classroom can never be an entirely safe space， nor， probably， should it be. But it's difficult to fault those who hope that it might be， when the outside world constantly proves itself pervasively hostile， as well as， on occasion， horrifically violent. Which of the following groups of people are most in favor of 'trigger warnings'? 查看材料