Dreams
　　Studies show that in dreams things are seen and heard rather than thought. In terms of the senses, visual experience is present in almost all dreams; auditory experience in 40 to 50 percent; and touch, taste, smell, and pain in a relatively small percentage. A considerable amount of emotion is commonly present, usually a pure and single emotion such as fear, anger, or joy.
　　Two clearly distinguishable states of sleep exist. The first state, called NREM-sleep （non-rapid- eye-movement sleep）, occupies most of the sleep period and is associated with a relatively low pulse and blood pressure, and few or no reports of dreaming. The second type of sleep, known as REM-sleep（rapid-eye-movement sleep）occurs cyclically during the sleep period with rapid eye movements and frequent dream reports. Typically, a person has four or five periods of REM-sleep during the night, whether the dreams are remembered often, rarely, or not at all; they occur at intervals of about 90 minutes and altogether make up about 25 percent of the night's sleep（as much as 50 percent in a newborn child）. Evidence indicates that a dream period usually lasts from 5 to 20 minutes. Sounds and touches working on a dreamer can go into a dream if they occur during a REM-period. Although mental activity may be reported during NREM-sleep, these are usually short pieces of thought like experiences.
　　Modern dream research has focused on two general interpretations of dream content. In one view, dreams have no meaning of their own but are simply a process by which the brain integrates new information into memories. In the other view, dreams contain real meaning symbolized in a picture language distinct from conscious logical though. If dreams express important wishes, fears, concerns, and worries of the dreamer, the study and analysis of dreams can help reveal previously unknown aspects of a person's mental functioning.
　　1. There are in general two opinions about what we experience in a dream:
　　A. one, we “see” our dreams, and two, we “think” our dreams.
　　B. one, we are happy, and two, we are angry.
　　C. one, dreams put new information into our memories, and two, dreams have real meanings in pictures different from our logical thinking.
　　D. we have pictures in dreams because one, we have slow eye movements, and two, we have rapid eye movements.
　　2. According to this article, we
　　A. often think seriously when we are dreaming.
　　B. hardly ever hear music when we are dreaming.
　　C. very often feel something tastes good when we are dreaming.
　　D. almost always see different “pictures” when we are dreaming.
　　3. In your dreams, you
　　A. very often feel happy and unhappy at the same time.
　　B. always feel that you are afraid of somebody.
　　C. seldom feel fear now and joy later.
　　D. only feel anger.
　　4. This essay tells us that
　　A. people usually dream in a NREM sleep.
　　B. people usually dream in an REM sleep.
　　C. people always remember what they have dreamed in an REM sleep.
　　D. people may have an REM sleep all night through.
　　5. Based on what is discussed in this writing, an adult may have at most about _______ of the time of his or her sleep dreaming.
　　A. 90%
　　B. 50%
　　C. 25%
　　D. 20%