单选题
People who do sleep research tell us that a person is a sort of "information processor." We have two ways to use the information we get each day.
The first process is used when we are awake. It takes place in the left side of the brain. It is this process that makes us do the things we have to do. It lets us put aside those things that are not a real part of our day"s work.
The second process happens in the right side of the brain. This process takes all those bits of information we did not use in the day. It turns them to dreams at night. "This process is our regular night shift work," says physiologist Rosalind Cartwright from the University of Illinois. "At night we put together the bits and pieces of our day, so that we are ready to face the next day."
We have several dreams each night of our lives. About ten minutes after we fall asleep, we begin to go through four stages of sleep. Our sleep gets deeper and deeper. And it gets harder for us to wake up. At the end of the fourth and deepest stage, the process changes. We begin to come back up again through the same stages. The coming back up is called "rousal" time. It lasts about ten to twenty minutes. We do not wake in this stage. Instead, we go through a stage of vivid dreams.
In this stage we do not toss or turn or even snore. The brain temperature and the blood flow get much higher. The body goes as limp as a rag doll. And the large muscles in the arms, legs, and trunk go stiff. The eyeballs begin to move back and forth very quickly, even though the eyes are closed. This is called the stage of Rapid Eye Movement or the REM stage.
We go into the REM stage about six times a night. That"s once every hour and a half or so. This hour and a half pattern is part of many things in our lives. Lots of body functions happen every hour and a half. Things like stomach contractions (收缩) and hormone secretions (分泌).
Why do we dream? Research tells us that dreams can help us with our probleMs. When we have big problems in the day, we may spend more time in REM sleep at night, because dreams can bring answers to problems.
单选题
Sleep research reveals ______.
【正确答案】
B
【答案解析】[解析] 本题要求考生把握文章的细节。文章第二段提到我们的左脑指挥我们该做的事情，把白天工作以外的一部分事情储存以来，因此B“左脑负责处理白天应做的工作”与此相符。AC在原文中都没有被提到；D项“右脑的职能是将白天未能处理的信息分类”，与第三段第二句“This process takes all those bits of information we did not use in the day.”不符合。故正确答案是B。
单选题
By calling the coming back up "rousal time", the author means in this stage ______.
【正确答案】
B
【答案解析】[解析] 本题要求考生把握文章的细节。文章第四段提到“The come back is called "rousal" time ... Instead, we go through a stage of vivid dreams”选项B人们的思想开始变得活跃与此意思相符。故正确答案是B。
单选题
During one"s REM stage ______.
【正确答案】
D
【答案解析】[解析] 本题要求考生把握文章上下文之间的细节逻辑关系。第四段说“The come back is called "rousal" time ... Instead, we go through a stage of vivid dreams.”紧接着，第五段说“In this stage we do not toss or turn or even snore ...”而此句中的in this stage指的就是REM stage。由此可知，D项“人可能进入一个生动的梦境”与此意思相符。而A项“除了胃部收缩和荷尔蒙分泌外身体的其他功能都停止作用”，文中提到胃部收缩和荷尔蒙分泌是作为人身体许多功能都是每一个半小时发生一次的例子，因此A项不对；而B“人的身体不停地运动”与文章第五段第一句“In this stage we do not toss or turn or even snore.”不符合，因此B不对；C项“身体和大脑都得到良好的休息”在文中没有被捉到，因此C项不对。故正确答案是D。
单选题
The example of hormone secretion is given in the passage to illustrate ______.