Passage One Questions 31 to 35 are based on the following passage: An American researcher has developed a device to help people stop snoring ( 打鼾 ). The device restricts the movements of the tissue ( 器官组织 ) that causes the bad sound. Snoring is a common problem. It may pr a person from getting enough sleep. It may also pr enough oxygen from reaching the heart and lungs during the sleep. But for most people, snoring affects relations with another person who must sleep in the same room. Snoring happens when the sleeping person breathes with the mouth open. In the back of the mouth the tissues surrounding the entrance of the throat are soft. As the person breathes, themovement of the air around the soft tissues causes them to move or vibrate. This tissue movement causes the sound we call snoring. A number of possible solutions have been proposed. Some devices keep the mouth shut. They forced the patient to breathe only through the nose. A medical operation is also possible. Other devices listen for the sound of snoring and then wake the patient. The new anti-snoring device was developed by a dentist (牙医 ), George Wagner of the Indiana University School of Dentistry. He developed a piece of plastic that fits up against the inside of the mouth. The device keeps the soft tissues from vibrating and the snoring noise. It was worn only at night. Doctor Wagner said several patients report that the device has ended theirsnoring problem.