精选优质文档-倾情为你奉上 Good morning, dear teachers and schoolmates. Im.and he (she) is.We are from class 1507. Today our topic is The Prevention of Epidemic Diseases in Autumn And Winter. As the end of year approaches, its getting colder and colder. With the decrease of temperature, its easier for the pathogens of respiratory disease to survive. Stimulated by cold air, the respiratory mucosas ability to defense against pathogens goes down. These two aspects make respiratory diseases
