7．Some colors people see late at night could cause signs of clinical（临床的）depression （沮丧）．That was the finding of a study that builds on earlier study findings．They show that individuals （个人） who live or work in low levels of light overnight （整夜） can develop clinical depression．Doctors use the word"clinical depression"to describe severe form of depression．Signs may include loss of interest or pleasure in most activities，low energy levels and thoughts of death or suicide．
In the new study，American investigators designed an experiment that exposed hamsters（仓鼠）to different colors．The researchers chose hamsters because they are nocturnal（夜行的），which means they sleep during the day and are active at night．
The animals were separated into four groups．One group of hamsters was kept in the dark during their night-time period．Another group was placed in front of a blue light，a third group slept in front of a white light，while a fourth was put in front of a red light．
After four weeks，the researchers noted how much sugary water the hamsters drank．They found that the most depressed animals drank the least amount of water．
Randy Nelson heads the Department of Neuroscience at Ohio State University．He says animals that slept in blue and white light appeared to be the most depressed．"What we saw is that these animals didn't show any sleep uneasiness （不安） at all but they did mess up biological clock genes and they did show depressive sign while if they were in the dim（微弱）red light，they did not．"
Randy Nelson notes that photosensitive（感光）cells in the eyes have little to do with eyesight．He says these cells send signals to the area of the brain that controls what has been called the natural sleep-wake cycle．
He says there's a lot of blue in white light．This explains why the blue light and white light hamsters appear to be more depressed than the hamsters seeing red light or darkness．
58．Researchers use hamsters in the experiment becauseD．
A．they are similar to humans in dealing with colors
B．they are easy to observe and study
C．they are sensitive to colors like human beings
D．they are active at night and sleep during the day
59．What sign shows that the hamsters are being depressed？A
A．They drink less sugary water．
B．They don't sleep well．
C．Their eyesight becomes worse．
D．Their energy level becomes low．
60．What can help people who work late at night to avoid being depressed？B
A．Not being exposed to dim red light when using computers．
B．Equipping their computer screens to put it more in the reddish light．
C．Living or working in low levels of light overnight．
D．Going to see doctors of clinical depression regularly for help．
分析 文章主要介绍的是一项科学研究．人们在深夜看到的一些颜色能够引起临床沮丧的症状．研究发现，整夜在较暗的环境中生活或工作的人可能会表现出临床沮丧．相关症状包括对活动失去兴趣和乐趣，精神不振和产生死亡或自杀念头等．
解答 58．D细节理解题．根据第二段The researchers chose hamsters because they are nocturnal，which means they sleep during the day and are active at night．可知研究者使用仓鼠，是因为它们在白天睡觉，晚上却出来活动．故选D．
59．A细节理解题．根据第四段"…the researchers noted how much sugary water the hamsters drank．They found that the most depressed animals drank the least amount of water"可知研究人员发现，压抑感最强的仓鼠喝的糖水最少．故选A．
60．B推理判断题．根据最后一段中的"This explains why the blue light and white light hamsters appear to be more depressed than the hamsters seeing red light or darkness"可知在红光或黑暗中，仓鼠的压抑感表现得比蓝光或白光中的仓鼠少．由此可知，B项中的让电脑屏幕多显现出一些红光的做法是可取的．故选B．
点评 本文是人物故事类阅读理解．做这类题材阅读理解时要求考生对文章通读一遍，做题时结合原文和题目有针对性的找出相关语句进行仔细分析，结合选项选出正确答案．推理判断题也是要在抓住关键句子的基础上合理的分析才能得出正确答案，切忌胡乱猜测，一定要做到有理有据．
