Passage TwoGenerations of Americans have been brought up to believe that a good breakfast is essential to one's life. Eating breakfast at the start of the day, we have been told, and told again, is as necessary as putting gasoline in the family car before starting a trip. But for many people, the thought of food as the first thing in the morning is never a pleasure So despite all the efforts, they still take no breakfast.Between 1977 and 1983, the latest year for which figures could be obtained, the number of people who didn't have breakfast increased by 33%from 8.8 million to 11.7 million--according to the Chicago-based Market Research Corporation of America．For those who dislike eating breakfast, however, there is some good news.Several studies in the last few years have shown that, for adults especially, there may be nothing wrong with omitting breakfast. "Going without breakfast does not affect work," said Arnold E. Bender, former professor of nutrition at Queen Elizabeth College in London, "nor does giving people breakfast improve work." Scientific evidence linking breakfast to better health or better work is surprisingly inadequate(不充分) ,and most of the recent work involves children, not adults. "The literature," says one researcher, Dr. Earnest Polite at the University of Texas, "is poor."What does the word "literature" in the last sentence refer to? ()