the following appeared in a letter to the editor of a newsletter on health issues.

　　"for the past decade, most health experts have advised teenagers to avoid eating greasy¹ foods in order to prevent acne and related skin conditions, but the number of teenagers who sought medical help for these skin problems has actually risen over the same period. in a recent study, teenagers who avoided greasy foods for a month reported approximately as many outbreaks of acne and related skin conditions as did those who ate an average of two servings of greasy food per day. such data indicate that eating greasy foods is unlikely to be a cause of acne and related skin conditions. therefore, health experts should no longer recommend that people avoid such foods."

　　from a draft textbook manuscript submitted to a publisher.

　　"as earth was being formed out of the collision of space rocks, the heat from those collisions and from the increasing gravitational energy of the planet made the entire planet molten, even the surface. any water present would have evaporated and gone off into space. as the planet approached its current size, however, its gravitation became strong enough to hold gases and water vapor² around it as an atmosphere. because comets are largely ice made up of frozen water and gases, a comet striking earth then would have vaporized. the resulting water vapor would have been retained in the atmosphere, eventually falling as rain on the cooled and solidified³ surface of earth. therefore, the water in earth's oceans must have originated from comets."

　　the following appeared in a medical newsletter.

　　"doctors have long suspected that secondary infections may keep some patients from healing quickly after severe muscle strain. this hypothesis has now been proved by preliminary results of a study of two groups of patients. the first group of patients, all being treated for muscle injuries by dr. newland, a doctor who specializes in sports medicine, took antibiotics⁴ regularly throughout their treatment. their recuperation time was, on average, 40 percent quicker than typically expected. patients in the second group, all being treated by dr. alton, a general physician, were given sugar pills, although the patients believed they were taking antibiotics. their average recuperation time was not significantly reduced. therefore, all patients who are diagnosed with muscle strain would be well advised to take antibiotics as part of their treatment."

　　the following appeared in a memo⁵ to the human resources manager at baobob inc., a large architectural firm.

　　"several well-known, retired⁶ architects were interviewed in architecture today about changes in the field. only one had earned a college degree in architecture. all others had come into the field at an early age by serving apprenticeships that required them to work under the direct supervision⁸ of an experienced architect. several of the colleges that we recruit from report that many promising⁹ architecture students leave school early in their undergraduate career. therefore, because finding talented architecture graduates is becoming more difficult, baobob inc. should start an aggressive apprenticeship⁷ program and hire students who express an interest in architecture directly out of high school rather than wait for them to get out of college."

　　thirteen years ago, researchers studied a group of 25 infants who showed signs of mild distress¹⁰ when exposed to unfamiliar¹¹ stimuli¹² such as an unusual odor or a tape recording¹³ of an unknown voice. they discovered that these infants were more likely than other infants to have been conceived in early autumn, a time when their mothers' production of melatonin—a hormone¹⁴ known to affect some brain functions—would naturally increase in response to decreased daylight. in a follow-up study conducted earlier this year, more than half of these children—now teenagers—who had shown signs of distress identified themselves as shy. clearly, increased levels of melatonin before birth cause shyness during infancy¹⁵ and this shyness continues into later life.