听力原文: American researchers have reported progress in learning how the ancient traditional Chinese method of acupuncture fights pain and other conditions. During acupuncture, very small, sharp needles are placed in the skin at targeted points on the body. Bruce Rosen presented an acupuncture study at a meeting of the American Psychosomatic Society in Orlando, Florida. Doctor Rosen is with the Harvard Medical School in Boston, Massachusetts. Doctor Rosen reported that the study findings could show how the brain might help people suffering from a number of health problems. These include pain, unexplained worry and sadness and some disorders of the stomach and intestines. The findings also may aid people who are fighting dependence on substances like illegal drugs. Doctor Rosen led a team that studied about twenty healthy people. The team examined the people with functional magnetic resonance imaging devices. MRI's can show changes in the flow of blood and the amount of oxygen in the blood. They studied the people before, during and after acupuncture. The researchers placed acupuncture needles in the skin on the people's hands. They chose places linked to pain relief in traditional Chinese acupuncture. Meat of the people reported that their hands felt heavy after the needles were placed. Blood flow to some areas of the brain decreased quickly in these people. Doctor Rosen said that was a sign that the acupuncture was working correctly. But a few of the people said their hands hurt. Their needles were probably not placed correctly. Their MRI's showed an increase in blood in the same areas of the brain where the other people showed a decrease. According to the findings by the American researchers, what is of help in relieving patients' pain and worry?