2012年职称英语考试-理工类C级阅读理解_0

1、12012年职称英语考试-理工类C级阅读理解Maki ng Light of1 SleepAll we have a clock located in side our bra ins. Similar toyour bedside alarm clock,your internal clock2 runs on a24-hour cycle. This cycle,called a circadianrhythm,helpscon trol whe nyou wake,when you eat and when you sleep.Somewhere around puberty,somet

2、hing happens in the2timi ng of the biological clock. Theclock pushes forward,so adolescents and teenagers are unableto fall asleep as early as they used to. When your mother tells you its timefor bed,your body may be pushing you to stay up3 for several hoursmore. And the light coming from your compu

3、ter scree n or TV could bepushi ng you to stay up eve n later.This shift4 is natural for teenagers. But staying up very late andsleeping late can get your bodys clock out of sync with the cycle of lightand dark5. It can also make it hard to get out of bed in the morning andmay bring other problems,t

4、oo.Teen agers are put in a kind of a gray cloud6 whe n they dont get eno ughsleep,says Mary Carskad on, a sleep researcher atBrow n Un iversity in Provide nee,RI7t affects their mood andtheir ability to thi nk and learn.But just like your alarm clock,your internal clock can bereset. In fact,it automatically resets3itself every day. How? By using the light it gets through your eyes.Scientists have known for a long time that the light of day and thedark of ni ght play importa nt roles in sett ing our internal clocks. Foryears,researchers thought that the signals that synchroniz