Research suggests that a newly-identified gene known as insomniacs(失眠癥患者) may play a role in keeping us asleep. By cloning and testing this gene in about 21,000 fruit flies, Rockefeller University researchers say they have discovered an entirely new mechanism (機(jī)制) by which sleep is controlled.
By studying these flies, the researchers discovered that mutations(變異) in the insomniac gene were associated with a great reduction in sleep. While a typical fruit fly slept for an average of 927 minutes a day, the mutant flies slept for just 317. They also slept for shorter periods of time, and slept and woke more frequently.
“The results showed a great loss of both the time that the flies’ sleep lasted and their ability to remain asleep after they slept,” says researcher Nicholas Stavropoulos.
The researchers also examined the link between sleep and lifespan, finding that flies with mutations to the insomniac gene lived only about two-thirds as long as unchanged flies. But when the scientists removed insomniac only in neurons(神經(jīng)細(xì)胞)---allowing it to remain in the rest of the flies’ bodies---this difference disappeared; the resulting animals slept poorly but lived just as long.
“This suggests that reduced sleep can be ‘uncoupled’(分開(kāi)) from reduced lifespan, supporting the idea that some interruptions of sleep do not affect overall health, at least as far as lifespan is concerned,” Stavropoulos says.
Although flies and humans would appear to have little in common when it comes to lifestyle, scientists say that the mechanisms of sleep and wakefulness are likely to be quite similar.
“Sleep is a fundamental behavior in all animals, and it is poorly understood from a scientific standpoint, says Stavropoulos. This work could prove useful in understanding and treating sleep disorders”
小題1:The text is mainly about____.
A.the progress in cloning fruit flies
B.the methods of cloning fruit flies
C.the link between gene and lifespan
D.the influence of a gene on the ability to sleep
小題2:According to paragraph2, the mutant flies________.
A.slept about 5 hours a day
B.had problems waking up
C.didn’t seem sleepy at all
D.could not fall asleep
小題3:We can conclude from the text that________.
A.sleep and health go hand in hand
B.sleep can be controlled by humans
C.research into sleep is very fruitful
D.the findings are useful in medical treatment

小題1:D
小題2:A
小題3:D

試題分析:本文敘述了通過(guò)對(duì)果蠅的科學(xué)研究發(fā)現(xiàn)基因影響睡眠的能力,而一般情況下果蠅睡眠平均每天927分鐘,變異果蠅睡了只有317分鐘,他們睡眠的時(shí)間更短了,睡著了,醒來(lái)時(shí)卻更頻繁。蒼蠅和人類在生活方式上似乎沒(méi)有什么共同點(diǎn),但是睡眠和清醒的情況也可能非常相似。這個(gè)研究發(fā)現(xiàn)可能對(duì)于治療睡眠障礙有一定的幫助。
小題1:主旨大意題。根據(jù)By studying these flies, the researchers discovered that mutations(變異) in the insomniac gene were associated with a great reduction in sleep.可知基因影響睡眠的能力,故選D。
小題2:細(xì)節(jié)理解題。根據(jù)the mutant flies slept for just 317,變異果蠅一天睡眠的時(shí)間大約5個(gè)小時(shí),故選A。
小題3:推理判斷題。根據(jù)This work could prove useful in understanding and treating sleep disorders,故選D。
點(diǎn)評(píng):主旨大意題的難度較大,此類題目一般不易直接找到答案,最簡(jiǎn)單的方法是仔細(xì)研究文章開(kāi)頭的一二句,因?yàn)樗麄兂J俏恼碌闹黝}句,然后,快速瀏覽文章首句和結(jié)尾句。如果第一句的主題不明,可注意結(jié)尾是否有概括總結(jié),對(duì)選項(xiàng)要注意全面性和概括性。
練習(xí)冊(cè)系列答案
相關(guān)習(xí)題

科目:高中英語(yǔ) 來(lái)源:不詳 題型:閱讀理解

There have been big changes in the attitudes of most parents over the last few years. Physical punishment is banned in schools in most countries, and in many countries, there are moves to ban all physical punishment of children even at home. However, many parents still believe that they have the right to use some physical punishments to deal with certain misbehavior at certain ages.
It’s easy to find reasons to allow some physical punishments. One issue is that many parents find it very difficult to abandon physical punishment completely. Parents argue that this was the way they were brought up and that it didn’t do any harm to them. They believe that for the child’s sake they have the right to discipline the child in any way they consider fit, including using some physical punishments. The other one is that physical punishment can be quick and effective. There is not much point reasoning with a screaming child in the supermarket.
However, there are several reasons why we should stop using physical punishment. One point is that most parents are not trained to deal with misbehaving children. They don’t have enough resources or choices to handle the situation. As a result, they immediately react by hitting the child even if there are other solutions to the problem. Another point is that unless people are challenged or forced to change their belief, they may keep following negative habits. An example is seat belt use —now most people wear seat belts without thinking, while years ago the idea of using seat belts was strange to most people. In the same way, banning physical punishment will force people to change their habits.
In conclusion, parents have to change some of their belief and ideas about how children should be raised. It is possible to avoid the use of physical force, and doing so will help us move closer to the dream of removing violence from our society.
小題1:According to the first paragraph, many parents think that ____________.
A.they are free to use physical punishment on their children
B.most of the children behave badly in their daily life
C.they have changed their attitudes towards their children
D.physical punishment is effective to educate their children
小題2:Many parents won’t give up physical punishment because _____________.
A.they are disappointed with their children
B.they were brought up just in the same way
C.they don’t want to hurt their children badly
D.they don’t know what to do with their children
小題3:The author gives the example of using seat belts in order to show ____________.
A.most people are used to wearing seat belts
B.it’s not difficult to change some negative habits
C.seat belts are really very necessary and useful
D.people won’t change their old habits unless forced
小題4:The main purpose of the author in writing this passage is to ____________.
A.talk about a ban on using physical punishment
B.tell us we should educate our children in other ways
C.a(chǎn)dvise parents to give up using physical punishment
D.suggest physical punishment should be used at home

查看答案和解析>>

科目:高中英語(yǔ) 來(lái)源:不詳 題型:閱讀理解

B
As an effect of the high fuel prices spent on bus transportation, some American schools are changing to a four-day week. That means longer days instead of the traditional Monday through Friday schedule.
Having been approved for three years and beginning in the fall, students in the Maccray school district in Minnesota will be in school from Tuesday to Friday. Each school day will be 65 minutes longer. Officials say the district expects to save about sixty-five thousand dollars a year in transportation costs.
In new Mexico, the first school district changed to a four-day week in 1974 because of the Arab oil boycott(抵制). Now, 17 out of 89 districts use it.
In Custer, South Dakota, students have been going to school four days a week since 1995. Superintendent Tim Creal says the change has saved about one million dollars over just the past eight years. He sees other benefits, too. Students get more instructional time, and activities that used to take up class time are now held on non-school days. He says that in the future, the growth of online classes could make it possible to require even fewer days in school. High fuel prices are driving college students to take more online classes.
A four-day school week sounds like a great idea for students and teachers, but working parents may have to pay for child care for that fifth day.
小題1:According to Tim Creal, what makes it possible to have even fewer days in school?
A.The increasing number of private tutors.(私人教師)
B.The development of teaching methods.
C.The increase in the number of online classes.
D.The growth in the income of Americans.
小題2: It can be learned from the passage that______
A.students will be in school from Monday to Tuesday.
B.four-day week was first carried out in South Dakota.
C.Maccray will save one million dollars every year.
D.Minnesota state has approved the four-day week plan
小題3:The passage is mainly about______
A.some school’s four-day week planB.districts using a four-day week.
C.how to save on transportation fees.D.expense of school transportation.

查看答案和解析>>

科目:高中英語(yǔ) 來(lái)源:不詳 題型:閱讀理解

There are two factors which determine an individual's intelligence. The first is the sort of brain he is born with. Human brains differ considerably, some being more capable than others. But no matter how good a brain he has to begin with, an individual will have a low order of intelligence unless he has opportunities to learn. So the second factor is what happens to the individual—the sort of environment in which he is reared (培養(yǎng)). If an individual is handicapped (妨礙) environmentally, it is likely that his brain will fail to develop and he will never attain the level of intelligence of which he is capable.
The importance of environment in determining an individual's intelligence can be demonstrated by the case history of the identical twins, Peter and Mark X. Being identical, the twins had identical brains at birth, and their growth processes were the same. When the twins were three months old, their parents died, and they were placed in separate foster homes. Peter was reared by parents of low intelligence in an isolated community with poor educational opportunities. Mark was reared in the home of well-to-do parents who had been to college. He was read to as a child, sent to good schools, and given every opportunity to be stimulated intellectually. This environmental difference continued until the twins were in their late teens, when they were given tests to measure their intelligence. Mark's I.Q. was 125, twenty-five points higher than the average and fully forty points higher than his identical brother. Given equal opportunities, the twins, having identical brains, would have tested at roughly the same level.
小題1:This passage can be best titled_________.
A.Intelligence and Environment
B.Measuring Your Intelligence
C.The Case of Peter and Mark
D.How the brain Influences Intelligence
小題2:According to the passage, the average I.Q. is _____.
A.85B.125C.110D.100
小題3:The case history of the twins appears to support the conclusion that _______.
A.individual with identical brains seldom test at same level
B.a(chǎn)n individual's intelligence is determined only by his environment
C.changes of environment produce changes in the structure of the brain
D.lack of opportunity blocks the growth of intelligence
小題4:This passage suggests that an individual's I.Q.______.
A.can be increased by education
B.stays the same throughout his life
C.can be predicted at birth
D.is determined by his childhood

查看答案和解析>>

科目:高中英語(yǔ) 來(lái)源:不詳 題型:閱讀理解

My son loves video games very much. He spends hours every day playing video games in his room. Is there any redeeming(補(bǔ)償?shù)模〆ducational value to video games? Some seem like they could help him learn strategy. But I worry others may be too violent or numb(使麻木)his mind.
Cecilia
Some games may improve kids’ hand-eye coordination and problem-solving skills. Games that require kids to actually move or manipulate(操縱)the game through their own physical movement can even get sedentary kids moving, though not as much as they could if they actually played outside or participated in sports or other outdoor acuities. Others, though, don’t have such benefits, and violent video games have been shown that they might increase kid’s aggressive behavior.
Like a lot of aspects of raising kids, when it comes to video games, the healthiest approach is actually self-control.
The American academy of Pediatrics(AAP) recommends that kids should spend no more than 2 hours each day on screen time, including watching TV or movies, or playing computer or video games. So consider setting limits at least that strict to keep game playing from affecting their schoolwork, household responsibilities, and the physical activity your son needs very day.
Make sure that he’s playing games which are suitable for his age group. All video games are rated and labeled by the Entertainment Software Rating Board. Steer clear of(避開(kāi))any rated “M” for mature. Those are for ages 17 and older and can contain heavy-duty violence, strong language, and sexual content.
Try to keep the video game console(游戲機(jī)控制板)in a common area of the house, not your son’s room. That way you can catch any inappropriate content in the games he’s playing, and he’ll be in a position to interact with others in the house while he’s playing.
Make sure your son has appealing alternatives, too, such as sports, activities, opportunities to socialize with peers; and downtime to be creative. If you continue to have concerns about his video game activity, talk with your doctor.
Reviewed by:Mary L. Gavin, MD
小題1:What is the opinion of Mary L. Gavin about playing video games?
A.Whether it’s beneficial or harmful depends on what the video games are.
B.It always improves kids’ hand-eye coordination and problem-solving skills.
C.It will make kids more violent and increase their aggressive behavior.
D.Kids should give it up and put their hearts fully into their schoolwork.
小題2:The underlined word “sedentary” in the first paragraph of the answer letter is the nearest in meaning to “______”.
A.unhealthyB.livelyC.brightD.inactive
小題3:According to Mary L. Gavin, which of the following is encouraged to do by parents?
A.Keep the video game console out of their house.
B.Allow their children to play only such video games as rated “M”
C.Let kids play video games as much as possible if it doesn’t affect their lessons.
D.Help their children develop other healthy hobbies such as sports and painting.
小題4:Which is the best title of this passage?
A.Should children play video games?
B.Kids’ playing video games is harmful.
C.Is playing video games good for kids?
D.Help children choose video games.

查看答案和解析>>

科目:高中英語(yǔ) 來(lái)源:不詳 題型:閱讀理解

The use of lotteries (彩票) to allocate (分配) school places is to be reviewed by the British government because more than 20 percent of children are failing to get into their first-choice schools in parts of the country.
The struggle for secondary school places has reached record levels this year, increasing anxiety for hundreds of thousands of families. A report from 43 local authorities suggests that in many areas, up to a fifth of children face disappointment. Families in London are the hardest hit.
This week is admissions week, when about 570,000 families will receive notice about their child’s secondary school acceptance. As the recession (不景氣) forces more parents to consider a state education rather than a private one for their children, more than a third of local authorities have noted rises in the number of applications for secondary school places.
This year, just 62 percent of children in Richmond-upon-Thames got into their parents’ first-choice school, down from 64 percent last year. The council said this was caused by an increase in applications.
In another London authority, Tower Hamlet, 71.1 percent of children were admitted to their parents’ first choice school. In Leeds and Warwickshire, 85 percent were successful. In Derby the figure was 81 percent, while in Wiltshire, Stockport and Lincolnshire, the figure was 89 percent.
In many authorities, the figures are similar to those of last year. Exceptions include Brighton and Hove, which introduced a lottery system to allocate oversubscribed places last year. This year, it has seen a 3.5 percent increase in the number of children obtaining their first choice, bringing the total to nearly 88 percent. However, more than 5 percent of children in this area have been allocated a place at a school that was not among any of their choices.
Lotteries are being used at the government’s suggestion by a small number of oversubscribed schools in around twenty-five local authorities. They were meant to prevent middle-class parents from abusing the system by buying or renting homes close to the best schools.
小題1:According to the passage, more and more parents in Britain prefer to send their children to _______.
A.a(chǎn) state schoolB.a(chǎn) private school
C.a(chǎn) school in LondonD.a(chǎn) school in Brighton
小題2:Which of the following statements is true according to the passage?
A.The lottery system is certainly a good way to allocate school places.
B.Over one in five children fail to get into their first-choice schools in parts of Britain.
C.The lottery system is welcomed by parents around twenty-five local authorities.
D.The number of applications for secondly school places is falling this year.
小題3:In the following places, the highest preferred school admission rate is in _______.
A.Richmond-upon-ThamesB.Brighton and Hove
C.LincolnshireD.Derby
小題4:The purpose of using lottery system is to ________.
A.keep middle-class parents buying or renting homes close to the best schools.
B.increase the number of children obtaining their first choice
C.decrease the number of applications for some good schools
D.create equality between children from different social classes
小題5:The passage is most probably taken from _______.
A.a(chǎn) survey on educationB.a(chǎn) textbook on science
C.a(chǎn) speech on radioD.a(chǎn)n essay on economy

查看答案和解析>>

科目:高中英語(yǔ) 來(lái)源:不詳 題型:閱讀理解

In my long years of teaching, I often ask my students to read the texts until they can recite them, and I tell them that recitation is an important part of their homework. However, some of my students are tired of doing so, thinking that it is both hard and useless. They argue that it takes a long time to recite a text from memory and text itself never appears in a test paper.
In my opinion, it naturally takes time to recite a text, but it is worth doing so. When you are able to recite a text, you are sure to be familiar with the words and expressions. When you need them in reading or writing or doing exercises, they will come to your mind quickly, and so you will give quick response to all kinds of language situation. How can we say that it is useless?
Besides, many students complain that they soon forget what they were once able to recite. This is true, but you don’t need to worry. While you are reading and forgetting the texts, your language   level is being raised. Sure you don’t remember your Chinese texts that you once read in the primary school, but now you are able to read novels and newspaper. So, recitation of the texts will help you improve your language ability.
小題1:The writer often asks his students to recite the texts, __________.
A.But they don’t like to do so
B.And they are eager to do so.
C.But they wrote a letter to the Department of the Education reporting the thing.
D.But they do more exercises instead of reciting the texts.
小題2:What do the students think about the teacher’s advice?_______
A.The English teacher tries his best to help them with English
B.The English teacher is very kind to them.
C.The English teacher asks them to do something useless.
D.The English teacher should let them study on their own.
小題3:According to the text, which of the following is correct_________.
A.The teacher thinks the students are too naughty to learn english well.
B.The students think they spend a lot of time in reciting the texts and get nothing.
C.The students say that they often forget the words.
D.The students take no interest in English.
小題4:When the students are against his suggestion, the writer_______.
A.often criticizes them
B.patiently explains to them why they should recite the texts
C.wants to give up his idea
D.is afraid that he is criticized by the headmaster.
小題5:Why does the writer suggest that the students recite the text?_____.
A.Reciting the texts can improve the ability of applying English.
B.Reciting the texts is the bestway of learning English.
C.The students should remember all the texts that the teacher has taught them.
D.Reciting the texts can greatly improve the classroom teaching

查看答案和解析>>

科目:高中英語(yǔ) 來(lái)源:不詳 題型:閱讀理解

Have you ever wondered why birds sing? Maybe you thought that they were just happy.After all,you probably sing or whistle when you are happy.
Some scientists believe that birds do sing some of the time just because they are happy.However,they sing most of the time for a very different reason.Their singing is actually a warning to other birds to stay out of their territory
Do you know what a “territory” is? A territory is an area that an animal,usually the male,claims(聲稱)as its own.Only he and his family are welcome there.No other families 0f the same species(物種)are welcome.Your yard and house are your territory where only your family and friends are welcome.If a stranger should enter your territory and threaten you,you might shout.Probably this would be enough to frighten him away.
If so,you have actually scared the stranger away without having to fight him.A bird does the same thing。But he expects an outsider almost any time,especially at nesting(筑巢) season.So he is screaming all the time,whether he can see an outsider or not This screaming is what we call a bird’s song,and it is usually enough to keep an outsider away.
Birds sing loudest in the spring when they are trying to attract a mate and warn others not to enter the territory of theirs.
You can see that birds have a language all their own.Most of it has to do with attracting mates and setting up territories.
小題1:Some scientists believe that most of the time birds’ singing is actually.
A.a(chǎn)n expression of happiness
B.a(chǎn) way of greeting
C.a(chǎn)n expression of anger
D.a(chǎn) way of warning
小題2:What is a bird’s “territory”?
A.A place where families of other species are not accepted.
B.An area which a bird considers to be its own
C.a(chǎn)n area for which birds fight against each other.
D.A place where a bird may shout at the top of its Voice.
小題3:Why do birds keep on singing at nesting season?
A.Because they want to invite more friends
B.Because their singing helps get rid of their fears.
C.Because they want to find outsiders around.
D.Because their singing helps frighten outsiders away.

查看答案和解析>>

科目:高中英語(yǔ) 來(lái)源:不詳 題型:閱讀理解

As a senior high school student, my future is always on my mind. To be exact,thoughts of the future have kept me up countless nights and made me worry enough to do poorly on more than one test. Because of this, words of wisdom are a source of comfort.Steve Jobs gave a speech to Stanford's graduating class in 2005 and his words resound repeatedly in my mind whenever I think about my future.
It started when l became a junior, when college came into view.  It's the first big step to making your life your own. So when Jobs discussed his life as a student, some fears were eased. He, too, felt the need to attend college to make something of himself. He faced what many are extremely afraid of: uncertainty. His lack of understanding caused him to stop attending college and focus on what he felt was important. His story had a happy ending, of course, since he certainly turned out well.
This doesn't mean that students shouldn't attend college, but rather that they shouldn't worry so much.  You'll get where you need to go, even if your path is a bit morewinding(蜿蜒的)than you'd like.
Jobs talked about the hardships in his work.  His love of his work helped him carry on and he got where he was meant to be, which restates the point: don't panic.One particular part of his speech stayed with me.  Steve Jobs quoted(引用)thc saying"Stay hungry, stay foolisll" and it has become my motto. Staying foolish is realizing thatyou are still a fool, no matter how much you've learned or experienced.  There is always more to explore. Staying hungry is wanting to find those things about which you are still uneducated.
Steve Jobs' level of success is possible to achieve, and I aim to prove that. With the will power to go into the world living every day like it's my last and allowing the future to take care of itself, I will do great things.  In the last moments of my life, I'll be proud of what I have done and hope to have all the wisdom a person could wish for.
小題1:The author felt worried when_____.
A.he had to take tests at school
B.he had lots of sleepless nights
C.he thought about his future
D.he searched for words of wisdom
小題2:It is suggested in Paragraphs l and 2 that_____
A.the author is a college student
B.the author cares much about his future
C.Steve Jobs failed because of his decision
D.Steve Jobs' words had no effect on the author
小題3:What did the author gain from Jobs' speech?
A.Courage to drop out of school.B.Confidence in defeating Jobs.
C.Interest in computer industry.D.Bravery to face uncertainties.
小題4:What did NOT Steve Jobs encourage students to do in his speech?
A.Be content with what they know.
B.Have the desire to learn more.
C.Stay calm in the face of hardships
D.Be modest so as to learn more.
小題5:The passage is mainly about_____.
A.a(chǎn)n experience of a speech
B.a(chǎn) memorable meeting with Jobs
C.the most impressive quotation in life
D.the wisdom drawn from a speech

查看答案和解析>>

同步練習(xí)冊(cè)答案