The fiddler crab (蟹) is a living clock. It shows the time of day by the colour of its skin, which is dark by day and pale by night. The crab’s changing colour follows a regular twenty—four hour plan that exactly matches the daily rhythm of the sun.
Does the crab actually keep time, or does its skin simply answer to the sun’s rays, changing colour according to the amount of light strikes it? To find out, biologists kept crabs in a dark room for two months. Even without daylight, the crab’s skin colour continued to change exactly on time.
This characteristic probably developed gradually in answer to the daily rising and setting of the sun, to help protect the crab from sunlight and enemies. After millions of years it has become completely regulated (受控制) inside the living body of the crab.
The biologists noticed that once each day the colour of the fiddler crab is especially dark, and that each day this happens fifty minutes later than on the day before. From this they discovered that each crab follows not only the rhythm of the sun but also that of the tides (潮水). The crab’s period of greatest darkening is exactly the time of low tide on the beach where it was caught!
小題1:The fiddler crab is like a clock because it changes colour ______.
A in a regular 24—hour rhythm              B. in answer to the sun’s rays
C. at low tide                            D. every fifty minutes
小題2:The crab’s changing colour ______.
A.tells the crab what time it isB.protects the crab from the sunlight and enemies
C.keeps the crab warmD.is of no real use
小題3: When the fiddler crabs were kept in the dark , they ______.
A.did not change colourB.changed colour more quickly
C.changed colour more slowlyD.changed colour on the same timetable
小題4:The crab’s colour—changing ability was probably developed ______.
A.in the process of evolution (進(jìn)化)B.over millions of years
C.by the work of biologistsD.both A and B
小題5:The best title for this selection would be ______.
A.The Sun and the TidesB.Discoveries in Biology
C.A scientific StudyD.A Living Clock

小題1:A
小題1:B
小題1:D
小題1:D
小題1:D
練習(xí)冊系列答案
相關(guān)習(xí)題

科目:高中英語 來源:不詳 題型:完形填空

I’m an operating engineer, running crane(起重機(jī)) in New York City. I was in the countryside, playing golf when we got the call that a plane had   36  the World Trade Centre. We checked out of the hotel immediately and started   37  our way downtown. When I got home, I called the rescue center and they told me to come   38  and get on the   39  list.
The next morning I went down to the   40  at about 5 A. M., and four hours later I   41  the call to come down to West Street. I called my wife and told her not to   42  me, and that I would stay in   43  with her. I took the subway. It stopped at West Fourth Street, so I had to   44  the rest of the way.
And somewhere in there I became   45  when I went into something I   46 . I once worked there in 1966 for the   47  of the World Trade Centre. On halfway on September 12, I was frightened to see the World Trade Centre was a huge pile, maybe ten   48  tall. And it was burning. I started to ask   49  in which my crane might be   50  a whistle blew suddenly warning us of some danger. I saw people running away and I really didn’t know what to do. So I did the same, too. It was as if they had   51  the bulls go in Spain and we were running through the street. People falling down, people   52  them up as they came by, and carrying them, just to get them out of the way, because something was extremely   53 . I didn’t even look back. We stopped running when we got to the Battery Tunnel, and I caught my   54  and said, “Oh, my God, I’m going to die.”
Then I 55  a little bit, thinking about what we should do next. As we started again we knocked into a fire chief officer and we asked, “What can we do to help you?”
小題1:
A.noticedB.reachedC.hitD.passed
小題2:
A.findingB.makingC.gettingD.losing
小題3:
A.a(chǎn)wayB.nearC.inD.down
小題4:
A.volunteerB.soldierC.policeD.fireman
小題5:
A.companyB.hotelC.centerD.home
小題6:
A.a(chǎn)nsweredB.madeC.heardD.received
小題7:
A.be curious aboutB.forget aboutC.laugh atD.worry about
小題8:
A.peaceB.touchC.connectionD.relation
小題9:
A.walkB.completeC.cancelD.smooth
小題10:
A.delightedB.frightenedC.embarrassedD.interested
小題11:
A.builtB.metC.designedD.had
小題12:
A.constructionB.planC.destructionD.use
小題13:
A.milesB.centimetersC.storiesD.floors
小題14:
A.meansB.numbersC.positionD.directions
小題15:
A.a(chǎn)sB.whyC.whenD.because
小題16:
A.drivenB.letC.a(chǎn)skedD.enjoyed
小題17:
A.pushingB.givingC.lookingD.picking
小題18:
A.dangerousB.urgentC.efficientD.important
小題19:
A.viewB.sightC.breathD.sense
小題20:
A.put downB.settled downC.knocked downD.let down

查看答案和解析>>

科目:高中英語 來源:不詳 題型:閱讀理解

I got married in 2008. My husband and I are very emotional and have loads of dreams in life. Now I want to share a hidden part of my life.
After one month of my marriage, I started working because I could not sit home. To accomplish our dreams, we are both working hard day and night in spite of belonging to a good family. Life is very strange. When any turn happens, one cannot know.
I started working because I was very ambitious. I used to wonder about people who worked to earn their bread but I never knew in my wildest dreams that I would be part of the crow who work to earn a livelihood.
I was blessed with a daughter in November, 2009. She was just three months and 15 days old when I rejoined my job. My husband supported me and my family supported me but I never wanted to work again because I belonged to a family where a mother should give her full attention to her child.
Keeping all the values aside that I learnt from my parents, I went back to work and will work till my last breath.
I missed my daughter every second. She has started recognizing and throwing expressions for likes and dislikes. I cannot share my feelings with anyone, as I do not want anyone to know that I am broken completely from inside.
My husband and my daughter are my greatest strength but I ignore them just to earn money and fulfill my dreams that I have.
If one day, my daughter complains to someone about her mom, please tell her that she is my reason for survival and happiness and she is the only one who brings smile to my face.
小題1:The author began to work after her marriage mainly because ____.
A.She expected to prevent herself from doing housework
B.She hoped to achieve her dream
C.She wanted to support her husband
D.She wanted to make her own bread
小題2: After her daughter’s birth, the author thought ____ in the beginning.
A.she should work harder
B.she should continue her career as she used to
C.she should stop working and care for her child
D.she should become a more ambitious mother
小題3:From the passage, we can know that the author’s daughter ____.
A.lives together with her mom now
B.hasn’t begun to learn to speak so far
C.a(chǎn)lways makes her mom heartbroken
D.has given much comfort to her mom
小題4:The author wrote this passage in order to ____.
A.complain about her present life
B.show her love for her daughter
C.keep a diary of her daughter’s growth
D.present the hardships of a working mother
小題5:What is the best title of this passage?
A.The secret of a working mother
B.A working family is continuing
C.A husband’s support for his wife’s career
D.The comparison between the family and career for a mother

查看答案和解析>>

科目:高中英語 來源:不詳 題型:閱讀理解

Much meaning can be conveyed, clearly, with our eyes, so it is often said that eyes can speak.
Do you have such kind of experience? In a bus you may look at a stranger, but not too long. And if he is sensing that he is being stared at, he may feel uncomfortable.
The same is in daily life. If you are looked at for more than necessary, you will look at yourself up and down to see if there is anything wrong with you. If nothing goes wrong, you will feel angry toward other’s stare at you that way. Eyes do speak, right?
Looking too long at someone may seem to be rude and aggressive. But things are different when it comes to stare at the opposite sex. If a man glances at a woman for more than 10 seconds and refuses to avert his gaze, his intentions are obvious. That is, he wishes to attract her attention, to make her understand that he is admiring her.
However, the normal eye contact for two people engaged in conversation is that the speaker will only look at the listener from time to time; in order to make sure that the listener does pay attention to hat the former is speaking, to tell him that he is attentive. 
If a speaker looks at you continuously when speaking, as if he tries to dominate you, you will feel disconcerted. A poor liar usually expose s himself by looking too long at the victim, since he believes the false ides that to look straight in the eye is a sign of honest communication.
In fact, continuous eye contact is confined to lovers only, who will enjoy looking at each other tenderly for a long time, to show affection that words cannot express.
Evidently, eye contact should be done according to the relationship between two people and specific situation.
小題1:Which of the following is TRUE according to the passage?
A.It is always very rude and aggressive to look at others for a long time.
B.One’s feelings can be shown through their eyes.
C.If a stranger looks at you for some time, he must be attracted at you..
D.If you are stared at by a stranger, you must look very awkward.
小題2:How can we tell if someone possibly lying?
A.If he looks at you directly in the eye for too long.
B.If he looks at you occasionally.
C.If he looks honest.
D.If he looks attentive.
小題3:What is suggested if you ate talking to others?
A. You’d better look at the listener all the time.
B. You are advised to try to dominate the listeners.
C. You are supposed to look at the listeners from time to time.
D. You should not make eye contact with listeners.
小題4:If two persons exchange eye contact gently for long, what is probably their relationship?
A.Father and son.B.Strangers.C.Lovers.D.Teacher and student.
小題5:Where can we read this passage?
A.In a textbook. .B.In a science journal.C.In a magazine.D.In a psychology report.

查看答案和解析>>

科目:高中英語 來源:不詳 題型:閱讀理解

BUILDING up a close bond (關(guān)系) with friends is important in all cultures. But different cultures have different ways of socializing.
The Chinese love going to restaurants. Family, friends and colleagues all go out to eat as a way of relaxing. So Chinese restaurants are much louder and noisier places compared with those in the Western world.
Although British people do socialize by going out for dinner, most people meet in pubs. They go there in the evening and sometimes during the day. Most people order wine or beer.
Going for a drink with colleagues after work is a particularly important British tradition. A recent survey of office workers found three-quarters of people regard the after-work drink as the key to building positive relationships with colleagues.
But for the French, the preferred place to socialize is in cafés. They are a central part of daily life in France and its culture. People will go to cafes at all times during the day.
In the morning, people may go there to buy a newspaper and a cup of coffee. At lunch they may go there for something to eat. Then when it's evening they may return to enjoy a glass of wine.
While the meeting place is different from culture to culture, "Essentially (本質(zhì)上) they serve the same purpose, which is that humans need a place to come together to meet," said Aidan Saunders, a professor of social history at the University College London. "We are sociable animals."
People from different parts of the world have different values, and sometimes these values are quite against each other. However, if we can understand them better, a multicultural environment will offer a wonderful chance for us to learn from each other.
小題1:What is the passage mainly about?      
A.Different cultures and different people.
B.Different places where different people love to go.
C.Different ways of building up relationships with friends
D.Different relationships in different countries.
小題2:Which of the following is true according to the passage?   
A.The Chinese love to dine out.
B.The Chinese always talk loudly in restaurants.
C.Making friends is an important thing in all countries
D.French people spend all their time in cafes.
小題3:What does Aidan Saunders mean by "We are sociable animals."?   
A.Human beings need society to survive in.
B.Human beings need to communicate with each other.
C.Human beings are the same as the other animals.
D.Human beings are also animals belonging to the society.
小題4: The following are all mentioned as ways of socializing except         .   
A.dining out with friends
B.drinking in pubs with colleagues after work
C.going to the cafes to have a cup of coffee
D.going to the cinema to see a film
小題5:Who are the intended readers of the passage ?        
A.People in general.B.Adolescents.
C.Business people.D.Educators.

查看答案和解析>>

科目:高中英語 來源:不詳 題型:閱讀理解

Shopping in the United States changes a lot.About ninety years ago most people shopped in small stores that were owned by one person or a family.Women went from the bakery to the butcher’s to the grocer and on to the fruit and vegetable seller in order to get their food for the week.Then, about sixty years ago, supermarkets were born.In a supermarket, people could get all the different kinds of food they needed without going to different stores.
The next big change in shopping in the United States was the shopping mall.A shopping mall is a group of stores under one roof.Because malls allowed people to shop without worrying about the weather, they soon became very popular.The mall became a place for people to socialize in addition to shopping.If you walk through a mall, you will see older people sitting, chatting and drinking coffee.Malls are places for teenagers to hang out.Many teens will often just “go to the mall” and spend time with their friends.
The recent change in American shopping was the superstore.Large chain stores such as Wal-Mart, Office Depot and Toys “R” Us have been built all across the United States.Because they are so large, they can buy goods at a great discount and sell them much cheaper than smaller stores.Sometimes, when they are built near small towns, many of the small town stores have to close.They just cannot compete with their giant neighbors.
And now, online shopping is becoming more and more popular all over the States.People are too busy to go to the physical stores, so they go shopping over the Internet.Online shopping has lots of advantages.For instance, online stores are usually available 24 hours a day.Searching or browsing online shops can be faster than browsing the physical stores.While, online shopping also has its disadvantages.People are at higher risk of being cheated on the part of the merchant than in a physical store.And privacy of personal information may be let out.
小題1:Which of the following shows the right order of shopping development in the United States?
①small stores ②superstores ③shopping malls ④shopping online ⑤supermarkets
A.①②③④⑤B.①⑤③②④C.②③④①⑤D.①⑤②③④
小題2:Which is the place for people to spend time with others according to the passage?
A.Small stores.B.Supermarkets.C.Shopping mallsD.Superstores.
小題3:Why can the superstores sell products at much lower prices?
A.Because they can buy goods at a reduction in price.
B.Because they are across the United States.
C.Because they sell all kinds of products people need.
D.Because they are built near small towns.
小題4:What’s the disadvantage of online shopping according to the passage?
A.Wasting time.B.Fixed prices.
C.No chance to do physical activities.D.Leaking personal information.

查看答案和解析>>

科目:高中英語 來源:不詳 題型:閱讀理解

Ok, I admit it: Emoticons(表情符號) are popular. Some people even think they are fun. Many seem unable to get through an e-mail or Instant Message chat sentence without using one. Some feel that they add feeling and character to otherwise cold digital communications.
Some, however, such as editor and Hollywood scriptwriter John Blumenthal, blast the use of emotions as “ infantile(幼稚的) just like the people who use them”. He believes that words themselves should be enough. “If you’re being funny, happy or sad, that should be apparent from the comment that goes before the emoticons,” he argues.
In the eyes of Blumenthal, the use of emoticons is a gender issue. “Men don’t use emoticons very much. Maybe not at all.,” he said. “Teenage girls and women seem to use them a lot. Maybe there’s an emoticons gene.”
It’s an interesting opinion, but it is not shared by all.
In an interview with The New York Times, Dacher Keltner, professor of psychology at the University of California, said that emoticons are popular because our brains are programmed “ to seek out representations of humanity”. He believes that they appeal not because they are shortcuts for the lazy, but because they tap into(輸入)something beyond language. They reach to our need to be with and communicate with people.
All of these arguments may be somehow valid(正確的). Each one of us will choose to communicate in our own way. I do not have much time for emoticons. I tried to use one once and felt like I was stealing into a primary school class that I had no place being in. I’d rather let my words do the talking.
Friends, however, send me messages and e-mails full of emoticons. I have no problem with this, I don’t regard any of my friends as lazy or immature. It’s just a question of individuality.
小題1:According to the article, emoticons are popular because_________.
A.most of them look funny
B.they are easy for lazy people to use
C.they add feeling and character to a communication
D.a(chǎn) reader cannot understand a message without them
小題2: Which of the following views would John Blumenthal agree with ?
A.Instant Message chatters are childish.
B.It’s enough to use language in digital communication.
C.Men never use emoticons.
D.There is an emoticon gene in everybody.
小題3:From the text, we can conclude that the author________.
A.feels he has no difficulty using emoticons
B.thinks emoticons don’t suit him
C.encourage his friends to use emoticons
D.believes that emoticons are suitable for everyone
小題4:What is the main point of the article ?
A.Advice on language used over the Internet.
B.The history of emoticons.
C.Arguments over the use of emoticons.
D.Reasons for the popularity of emoticons.

查看答案和解析>>

科目:高中英語 來源:不詳 題型:閱讀理解

For a while, my neighborhood was taken over by an army of joggers.(慢跑者). They were there all the time—early morning, noon, and evening. There were little old ladies in gray sweats, young couples in Adidas shoes, middle-aged men with red faces. “Come on!” My friend Alex encouraged me to join him as he jogged by my house every evening. “You'll feel great.”
Well, I had nothing against feeling great and if Alex could jog every day, anyone could. So I took up jogging seriously and gave it a good two months of my life, and not a day more. Based on my experience, jogging is the most overvalued form of exercise around, and judging from the number of the people who left our neighborhood jogging army. I'm not alone in my opinion.
First of all, jogging is very hard on the body. Your legs and feet a real pounding (沉重的腳步) running down a road for two or three miles. I developed foot, leg, and back problems. Then I read about a nationally famous jogger who died of a heart attack while jogging, and I had something else to worry about. Jogging doesn't kill hundreds of people, but if you have any physical weaknesses, jogging will surely bring them out, as they did with me.
Secondly, I got no enjoyment out of jogging. Putting one foot in front of the other for forty-five minutes isn't my idea of fun. Jogging is also a lonely pastime. Some joggers say, “I love being out there with just my thoughts.” Well, my thoughts began to bore me, and most of them were on how much my legs hurt.
And how could I enjoy something that brought me pain? And that wasn't just the first week: it was practically every day for two months. I never got past the pain level, and pain isn't fun. What a cruel way to do it! So many other exercises, including walking, lead to almost the same results painlessly, so why jog?
I don't jog any more, and I don't think I ever will. I'm walking two miles three times a week at a fast pace, and that feels good. I bicycle to work when the weather is good. I'm getting exercise, and I'm enjoying it at the same time. I could never say the same for jogging, and I've found a lot of better ways to stay in shape.
小題1:From the first paragraph, we learn that in the writer's neighborhood ________.
A.jogging became very popular
B.many people were encouraged to jog
C.Alex organized an army of joggers
D.jogging provided a chance to get together
小題2: The underlined word “them”(Paragraph 3) most probably refers to ________.
A.heart attacksB.Back problems
C.hundreds of peopleD.physical weaknesses
小題3: From the author's experience, we can conclude that ________.
A.jogging can help people keep fit
B.many physical problems result from jogging
C.not everyone enjoys jogging
D.jogging makes people feel great

查看答案和解析>>

科目:高中英語 來源:不詳 題型:閱讀理解

Ask just about any college student you know,and he is likely to tell you that he is a member of facebook.com.Many students say they check their e-mail.It’s so popular “facelooking”has become a verb “Everywhere everyone is doing it,”college student Katie Silverman said,“It’s like everyone’s center of life.”
Facebook is an online social meeting place where students create profiles (簡介),share personal information, and meet other members. It is password protected and targeted to high school and college students;members must have an edu.email address to join.
Many students say it has changed their social lives, giving them an easy way to find and chat with classmates who share their interests.“Some people might be too shy to go to talk to someone they like in one of their classes,but on facebook it’s a lot easier to strike up a conversation,”said Rahul Vanjani.
The website was founded by two Harward University students who wanted to meet more of their classmates.It became so popular that the website is at 2,200 colleges and at 22,000 high schools.It says that it has 6 million active users,two—thirds of whom are on it every day.Many of the facebook members said their parents had no idea they were on it .“No way.My parents certainly don’t know about it,” said a college senior who asked us not to use his name.
To keep it popular,Facebook says it stops students posting improper information.Some students have paid the price.At Fisher College in Boston,two students were kicked out for using facebook.com to do something that is against the law.At North Carolina State University,four students were punished for posting photos about drinking.
小題1:The passage is mainly about____.
A.student’s idea about Facebook
B.the development of Facebook
C.the popularity of Facebook with students
D.the rules of Facebook
小題2:To become a member of Facebook,you must_____.
A.have an edu,e—mail dress
B.have your own profile
C.be a high school student
D.offer main personal information
小題3:By saying “Some students have paid the price”in the last paragraph,the author means more students_____.
A.will have to pay money for being on Facebook
B.a(chǎn)lways use Facebook to do something against the law
C.have been punished for doing some improper things on Facebook
D.often stop others from posting improper information on Facebook
小題4:We can learn about Facebook from the passage that______.
A.the information that students offer to Facebook is secret to others
B.Facebook is at more colleges that at high schools
C.6 million active users of Facebook are on it every day
D.many students don’t want their parents to know they are facebooking

查看答案和解析>>

同步練習(xí)冊答案