听力原文： The First Amendment of the Constitution in the United States protects citizens' rights to free speech. Yet, more and more people have called for censorship. They have expressed their outrage for what is printed in books, depicted in paintings and photographs, written in songs, or demonstrated at political gatherings. Because of this outrage, many books have been censored from school libraries, art has been denied public funding, musicians have had concerts canceled, and political demonstrations have been limited. Probably the most extreme censor ship proposal in the U. S. has been to amend the Constitution to prohibit the burning of the U. S. flag, an act sometimes practiced by those who want protest against American policies. These advocates of censorship range from the politically conservative to the politically liberal. In the South, for example, many conservative communities, while fighting to include time in school for prayer, are fighting to ban particular children’s books. Some African-American parents even reject Mark Twain’s Huckleberry Finn because of the book's use of 'racist' language. Liberal feminists, too, have called for bans on published materials containing pornography. Censorship proposals are not only common in the world of books, but also in the worlds of art and music. Why do a lot of people in the United States call for censorship?