16.Some people can stay up all night and still get work done the next day.I'm not one of them.After a night without enough sleep,I feel bad-tempered.I have trouble remembering things.And all I want to do is to crawl into bed and sleep.
How do you feel after you've stayed up late to finish schoolwork?Or the day after an overnight party?Scientists now say that your answers to these questions may depend on your genes.
New research suggests that a gene called"period 3"affects how well you function without sleep.The"period 3"gene comes in two forms:short and long.Everyone has two copies of the gene.So,you may have two longs,two shorts,or one of each.Your particular combination depends on what your parents passed on to you.
Scientists from the University of Surrey in England studied 24people who had either two short or two long copies of"period 3".Study participants had to stay awake 40hours straight.Then,they took tests that measured how quickly they pushed a button when numbers flashed on screen and how well they could remember lists of numbers.
Results showed that the people with the short form of"period 3"performed much better on these tests than the people with the long form did.In both groups,people performed worst in the early morning.
After the first round of experiments,participants were finally allowed to sleep.People in the group that performed well on the tests (those with the short form of"period 3") took about 18minutes to nod off.
People with the long"period 3"gene,by contrast,fell asleep in just 8minutes.They also spent more time on deep sleep.That suggests that people with the long form of the gene need more and deeper sleep to keep their brains working in top form.
I think I must have the long form of"period 3".What about you?
28.The purpose of this passage might beB.
A.to tell us the importance of plenty of sleep
B.to tell the result of a research on sleepy gene
C.to inform the harm of lacking sleep
D.to announce the sleeping rules of humans
29.Which of the following decides how well you perform without sleep?D
A.One short form.
B.One long copy.
C.One short and two long copies.
D.Period 3.
30.What kind of people need less sleep according to the research?B
A.Those with two long copies of the gene.
B.Those with two short copies of the gene.
C.Those with one short and one long copy of the gene.
D.Those with three short copies of the gene.
31.If one lacks enough sleep,one should avoid doing important or dangerous thingsA.
A.in the early morning B.a(chǎn)t night
C.in the afternoon D.a(chǎn)t noon.
分析 文章介紹了一項關(guān)于睡眠的實驗,并從中得出了一定的實驗結(jié)果.
解答 28.B 主旨大意題.文章的目的就是介紹一項關(guān)于睡眠的實驗結(jié)果(文章第三段為主題段)所以答案選B.
29.D 細(xì)節(jié)理解題.人們?nèi)狈λ邥r表現(xiàn)的好壞由"period 3"決定.根據(jù)第三段第一句話New research suggests that a gene called"period 3"affects how well you function without sleep.新的研究表明,一個名為"周期3"的基因會影響你的睡眠功能 可知答案為D.
30.B 細(xì)節(jié)理解題.由文章第五段Results showed that the people with the short form of"period 3"performed much better on these tests than the people with the long form did 結(jié)果表明,與"長形式"的人相比,短周期"3期"的人在這些測試中表現(xiàn)更好 可得出答案為B.
31.A 推理判斷題.根據(jù)第五段第二句In both groups,people performed worst in the early morning.得出答案.缺乏睡眠的人在黎明時表現(xiàn)最差,因此不能在此時做重要或危險的事情,所以答案選A.
點評 閱讀理解題測試考生在閱讀基礎(chǔ)上的邏輯推理能力,要求考生根據(jù)文章所述事件的邏輯關(guān)系,對未說明的趨勢或結(jié)局作出合理的推斷;或根據(jù)作者所闡述的觀點理論,對文章未涉及的現(xiàn)象、事例給以解釋.考生首先要仔細(xì)閱讀短文,完整了解信息,準(zhǔn)確把握作者觀點.