英译汉－选译题
Ask mothers why babies are constantly picking things up from the floor or ground and putting them in their mouths, and chances are they’ll say that it’s instinctive - that that’s how babies explore the world. But why the mouth, when sight, hearing, touch and even scent are far better at identifying things?
Since all instinctive behaviors have an evolutionary advantage or they would not have been retained for millions of years, chances are that this one too has helped us survive as a species. And, indeed, accumulating evidence strongly suggests that eating dirt is good for you.
In studies of what is called the hygiene hypothesis, researchers are concluding that organisms like the millions of bacteria, viruses and especially worms that enter the body along with "dirt" spur the development of a healthy immune system. Several continuing studies suggest that worms may help to redirect an immune system that has gone awry and resulted in autoimmune disorders, allergies and asthma.
One leading researcher, Dr. Joel Weinstock, the director of gastroenterology and hepatology at Tufts Medical Center in Boston, said in an interview that the immune system at birth "is like an unprogrammed computer. It needs instruction."
He said that public health measures like cleaning up contaminated water and food have saved the lives of countless children, but they "also eliminated exposure to many organisms that are probably good for us."
考试用书"Children raised in an ultra-clean environment," he added, "are not being exposed to organisms that help them develop appropriate immune regulatory circuits."
Studies he has conducted with Dr. David Elliott, a gastroenterologist and immunologist at the University of Iowa, indicate that intestinal worms, which have been all but eliminated in developed countries, are "likely to be the biggest player" in regulating the immune system to respond appropriately, Elliott said in an interview. He added that bacterial and viral infections seem to influence the immune system in the same way, but not as forcefully.
Most worms are harmless, especially in well-nourished people, Weinstock said. "There are very few diseases that people get from worms," he said. "Humans have adapted to the presence of most of them."
Ruebush deplores the current fetish for the hundreds of antibacterial products that convey a false sense of security and may actually foster the development of antibiotic-resistant, disease-causing bacteria. Plain soap and water are all that are needed to become clean, she noted.
