It's a fact that we all dream. Some dreams seem to last for hours, others only for seconds

It's a fact that we all dream. Some dreams seem to last for hours, others only for seconds. Some of us have strange dreams, some have interesting dreams, and some of us have unpleasant dreams. Tests in the 1980s showed that these dreams occur within 90-minute cycles, each cycle made up of six stages. In the last stage people experience rapid eye movement, known as REM, and it is in this stage that dreaming takes place. Eighty percent of people who were woken during this sixth stage could easily remember their dreams. On the other hand, when during the first five stages (NREM), only seven percent could describe a dream.
However, of these same people woken during the first five stages, 74% were able to remember thinking activity, although they would not call it a dream. NerysDee, who has written about dreams in a book called Your Dreams and What They Mean says: Perhaps during NREM sleep we are sorting out our outer mundane problems, but in REM sleep we are dealing with inside matters. She also makes the following statement about 90-minute cycle: It may also prove the reason why insomniacs who wake in the middle of the night find it impossible to get to sleep again for at least an hour and a half. In other words, until they have missed out one complete 90-minute sleep period.
【小题1】Which of the following statements about dreams is TRUE?A．Everyone dreams but very few can recall what they dream.B．Some people have long dreams and others have very short ones.C．People can only remember unpleasant dreams.D．More than eighty percent of people can remember their dreams.【小题2】According to the tests in the 1980s, dreaming takes place­­ .A．between each 90-minute cycleB．at any time during 90-minute cyclesC．during the first five stages of 90-minute cyclesD．in the last stage of 90-minute cycles【小题3】People woken during REM sleep can .A．hardly remember their dreamsB．easily remember their dreamsC．only remember their dreamsD．partly remember their thinking activity【小题4】Insomniacs are persons who .A．can always remember their dreamsB．have trouble getting into sleep at nightC．experience rapid eye movementD．usually wake after each 90-minute sleep periodB

(答案→)B 解析：文章讲述的是有关“梦”的研究。每个人都做梦，有的梦持续时间长，有的却很短。有测试显示，梦每隔90分钟循环一次，一个循环经历六个阶段。人们常说的做梦，发生在第六个阶段。【小题1】根据第一段“It's a fact that we all dream. Some dreams seem to last for hours, others only for seconds.”可知，有的梦持续很长时间，有的却很短暂。故选B。【小题2】根据第一段“these dreams occur within 90-minute cycles, each cycle made up of six stages. In the last stage people experience rapid eye movement, known as REM, and it is in this stage that dreaming takes place.”可知，梦以90分钟为一个循环，每个循环分为六个阶段，做梦发生在第六个阶段，故选D。【小题3】根据第一段“In the last stage people experience rapid eye movement, known as REM, ...Eighty percent of people who were woken during this sixth stage could easily remember their dreams.”可知，在第六阶段即快速眼动阶段醒来的话，很容易记得梦境，故选B。【小题4】根据“who wake in the middle of the night find it impossible to get to sleep again for at least an hour and a half.”可知，划线词指的是夜里醒来以后很难再次入睡，这个状态持续一个半小时，故选B。

谢谢了