It is easy for us to tell who our family members are, but do plants recognize(識(shí)別) their own family? Some do, scientists say, according to a report by Science News in early 2010.
Guillermo P. Murphy and Susan Dudley are two plant scientists from McMaster University in Hamilton, Canada. They did a few experiments with Jewelweeds, a kind of flower that grows in wet, shady spots. They found that the flowers seem to know their own flower family. In their experiments, Murphy and Dudley planted jewelweeds in pots with either siblings or strangers.
When jewelweeds were planted in pots with strangers, the plants started to grow more leaves than if they had been planted alone. This response(反應(yīng))suggests that plants are competing with strangers for sunlight, since a plant with more leaves can receive more light and make more food. Jewelweeds usually grow in the shade, where sunlight is not enough.
When jewelweed seedlings(幼苗)were planted with siblings, they grew a few more branches than they usually would if they were alone – but they did not start growing lots of extra leaves. This behavior suggests the plants are more likely to share resources, rather than compete.
According to the Science News report, Jewelweeds are not the first plants that plant scientists have studied for family recognition. In 2007, Dudley and her team studied the Great Lakes sea rocket, a plant that grows on the beach – where it may be hard to get fresh water. In that experiment, the scientists found that when sea rockets were planted with siblings, they tolerated each other. But when they were planted with strangers, the sea rockets reacted by working extra hard to grow lots of roots.
Dudley says this just because sea rockets, on the beach, get plenty of sun but struggle for water – so when they’re threatened, they compete for water. Jewelweeds have plenty of water but have to compete for sunshine, so they grow more leaves.
小題1: What does the underlined word siblings mean?
A.Flowers come from foreign countries.
B.Plants growing in different environments.
C.Flowers planted with lots of strangers.
D.Plants that are the same kind.
小題2: In the text, the writer mentioned the experiments of Jewelweeds to         .
A.make a comparisonB.introduce a topic
C.describe a pretty flowerD.build a new theory
小題3: According to the passage, flowers planted alone will         .
A.grow more leaves than those planted in groups
B.become taller than those with more branches
C.grow fewer leaves than those planted with strangers
D.become ill easily because they can’t get enough shade
小題4: What can be the best title for the passage?
A.New Discoveries about Plants
B.How Plants Compete with Each Other
C.Family Recognition among Plants
D.Jewelweeds and the Great Lakes Sea Rockets

小題1:D
小題2:B
小題3:C
小題4:C

試題分析:這篇文章講的是科學(xué)家通過做實(shí)驗(yàn),發(fā)現(xiàn)將一種植物與不同種類的植物種植在一起,它會(huì)和其他植物競(jìng)爭(zhēng)養(yǎng)分,將會(huì)長的更好,如果單獨(dú)種植的話,則會(huì)分享資源,而不競(jìng)爭(zhēng)。
小題1:推斷題。由第二段最后一句In their experiments, Murphy and Dudley planted jewelweeds in pots with either siblings or strangers.在他們的實(shí)驗(yàn)中,Murphy and Dudley將鳳仙花要么和同類植物種植在一起,要么和不同的植物種植在一起。由后面的詞義可推出siblings的意思是同類植物。故選D
小題2:推斷題。從第一自然段Some do, scientists say, according to a report by Science News in early 2010.可知植物也能夠分辨出它的同類,第二自然段對(duì)這個(gè)說法進(jìn)行了一項(xiàng)有關(guān)jewelweeds鳳仙花的研究,所以在此是為了點(diǎn)明主題。
小題3:細(xì)節(jié)題。由第三段第一句When jewelweeds were planted in pots with strangers, the plants started to grow more leaves than if they had been planted alone.當(dāng)把鳳仙花和不同種類的植物種植在一起時(shí),它就會(huì)比單獨(dú)種植時(shí)生長出更多的葉子。故可知,答案選C
小題4:主旨題。這篇文章講的是科學(xué)家通過實(shí)驗(yàn),發(fā)現(xiàn)植物也可以辨別出哪些植物與自己是同一種類的。故選C.
點(diǎn)評(píng):本文較難,科技類的文體是比較繁瑣的,因?yàn)閷S忻~較多。學(xué)生在解答這類題目時(shí),首先對(duì)文章有大致的掌握,對(duì)于文章一遍沒有看懂時(shí),可以先看題目,按照文章題目的提示,再在文章中找出相對(duì)應(yīng)的地方,然后仔細(xì)分析文章的上下文,同時(shí)對(duì)于專有名詞可以用筆畫出,通過多個(gè)地方的比較就可以猜出意思了。
練習(xí)冊(cè)系列答案
相關(guān)習(xí)題

科目:初中英語 來源:不詳 題型:閱讀理解

With more and more farmers working in big cities, their children go into the cities, too.However, problems appear. One of these problems is that is difficult for these children to receive education in cities.
Luckily, there are some free schools for them, but they are not enough. Ten-year-old Li Xin is one of the lucky girls who get a chance to study in one of these schools. She is very happy. She studies in a school specially for migrant workers’(外來務(wù)工人員的)children. For children like Li Xin who don’t have enough money, these free schools are their best choice, because they have free classes, textbooks, uniforms and meals in the schools.
But there is a long way to go. The free schools for children from migrant workers’ families are not enough because to run such a school is not easy and needs lots of money. A school officer said they needed at least one million yuan to run the school. “Luckily, some people and companies donate(捐贈(zèng))money, used books and a lot of other things to help us. There are also some volunteers teachers,” he added.
Anyhow, we must try to give these children an equal(平等)chance to get better education so that we can make our society harmonious(和諧的).
小題1:From the passage, we know that Li Xin’s parents used to be __________.
A.workersB.teachers
C.officersD.farmers
小題2:The school provides Li Xin with the following things free except_____.
A.textbooksB.uniforms
C.computersD.meals
小題3:What does the underlined word “run” mean in Chinese in the passage?
A.奔跑B.經(jīng)營C.考慮D.收購
小題4:The passage mainly talks about__________.
A.what jobs migrant workers can do in big cities
B.the development of big cities
C.helping migrant workers’ children go to school
D.what difficulties those free schools face now

查看答案和解析>>

科目:初中英語 來源:不詳 題型:閱讀理解

Miss Liu is an English teacher. She is very young. She works very well and the students all like her. There are twenty-six boys and twenty-four girls in her class. Now some of them are playing on the playground. Jim and Bill are jumping. Sam and Mike are running. Lucy and Simon are singing. The other girls are playing games with their teacher. They’re happy.
小題1:Miss Liu is______.
A.a(chǎn) Chinese teacherB.very old
C.a(chǎn)n English teacherD.not good
小題2:There are _____ students in Miss Liu’s class.
A.26B.40C.24D.50
小題3: The students are ______.
A.a(chǎn)t workB.a(chǎn)t home
C.a(chǎn)ll happyD.in the classroom
小題4: Who is singing?
A.Miss LiuB.Lucy and Simon
C.Sam and MikeD.Jim and Bill
小題5:All the students _________.
A.like Miss LiuB.a(chǎn)re running
C.a(chǎn)re playing gamesD.a(chǎn)re jumping

查看答案和解析>>

科目:初中英語 來源:不詳 題型:完形填空

完形填空(10分)
  What will our life be like in the future? Each family will have a  1 in the future. You can ask it to do everything  2  you. It will serve(服務(wù)) you  3 hours a day. The robot will  4 like a human. It can talk with you when you are  5 . You won’t know it is a human  6 a robot when you meet it on the street.
  People will have  7 time to work and more time to travel. The vehicles(交通工具) in the future will fly freely in the sky because every vehicle will have wings(翅膀) with it. They will  8 you to any place you want to visit. You can go to  9  when you have a travel if you feel tired. All vehicles will be  10  because of driving by robots.
小題1:A、rocket              B、robot               C、car
小題2:A、on                 B、about               C、for
小題3:A、eight              B、twenty              C、twenty-four
小題4:A、sound              B、live                C、look
小題5:A、happy              B、alone               C、comfortable
小題6:A、so                 B、and                 C、or
小題7:A、less               B、few                 C、more
小題8:A、make               B、take                C、let
小題9:A、school             B、work                C、sleep
小題10:A、safe              B、dangerous           C、unpleasant

查看答案和解析>>

科目:初中英語 來源:不詳 題型:閱讀理解

Some people think that as more and more people have televisions in their homes, fewer and fewer people will buy books and newspapers. Why read an article in the newspaper, when the TV news can bring you the information in a few minutes and with pictures? Why read the life story of a famous man, when a short television program can tell you all that you want to know?
Television has not killed reading, however. Today, newspapers sell in very large numbers. And books of every kind are sold more than ever before. Books are still a cheap way to get information and enjoyment. Although some books with hard covers are expensive, many books are printed today as paperbooks (平裝本), which are quite cheap. A paperback collection of short stories, for example, is always cheaper than an evening at the cinema or the theater, and you can keep a book for ever and read it many times.
Books are a wonderful provider of knowledge and pleasure and some types of books should be in every home. Every home should have a good dictionary. A good encyclopedia (百科全書), though expensive, is useful, too, because you can find information on any subject. Besides, you can have such books as history books, science textbooks, cookbooks, and collections of stories and poems. Then from time to time you can take a book of poems off your shelves and read the thoughts and feelings of your favorite poets.
小題1:It can be inferred from the passage that ____.
A.Fewer and fewer people will buy books.
B.A good dictionary should be kept in every home.
C.Books with hard covers sell better than paperbooks.
D.More people like TV programs about famous men.
小題2:What does the sentence “Television has not killed reading, however.” underlined in the second paragraph suggest?
A.People only need reading, though.
B.Reading is still necessary today.
C.Reading is more fun than television.
D.Watching television doesn’t help reading.
小題3:What can we learn from the passage?
A.TV programs are a chief provider of knowledge.
B.Cinemas are the best choice in getting information.
C.Reading is cheap way of learning and having fun.
D.Newspapers are an expensive way to enjoy oneself.

查看答案和解析>>

科目:初中英語 來源:不詳 題型:閱讀理解

閱讀短文,從所給的選項(xiàng)中選擇四個(gè)句子完成短文,使其文理通順。(有一項(xiàng)多余)
Imagine a normal day: you go to work, return home, and maybe buy somethings on your way home.小題1:. For a large number of people, the answer to that question is zero.
Ever since the Industrial Revolution(工業(yè)革命)began, many changes have taken place in our world.小題2:.
Want to buy a pair of shoes? An MP3 player? A book? It’s only a few clicks(點(diǎn)擊) away. Need a computer? A gift? A tennis racket? Click. No need to even leave your house.小題3:And the quality of crops that are grown and harvested(收割) by computers is getting better.
You are probably booking (預(yù)定) your hotel room online. When can we choose our own rooms and get our keys by ourselves? We also hope that everything we want to buy at the supermarket will be ready for us when we arrive.小題4:Researchers have already designed a robot to correctly find your preferred beer and bring it to you.
Will human jobs be completely done by robots? We don’t know. But computers are doing more and more jobs for humans.
小題5:How many examples of ways of doing things does the author pick up to show the advantages of computers?
A. Five.  B. Four.  C. Six.  D. Three.
A. On the farm, machines are used, and more and more farm jobs can be done by machines.
B. In a factory, workers are busy making products.
C. Many jobs done by humans in the past are now being done by technology(技術(shù)) instead.
D. How many people do you have to talk with to do those everyday tasks?
E. In fact, a restaurant in China recently started using some robots to serve people.
 

查看答案和解析>>

科目:初中英語 來源:不詳 題型:閱讀理解

Very few people enjoy exams. I don’t, either. And although I tell myself not to worry about them, I always do! So I’m not surprised that my students worry about them, too, even though they usually don’t need to. Because they are afraid of failing. However, since it is hard not to worry at all, we all must try not to worry too much. Why? Because worrying makes exams worse! How to do this?
Ask the teacher about how to revise and about exam skills—how to work when you are in the exam. Good students don’t wait until the week before an exam. They study all through the year. It is not possible to learn everything at the last minute. So don’t leave it till then.
If you start planning and working for each exam early and you make sure that you understand what you’re studying, then, when it is over, you’ll be able to say, “What a good exam that was!”
Take a short rest during your time of work and revision. If your mind is tired, it won’t remember well. Work at the time when you know you’ll work at your best.
If you’re studying in the evening, don’t go straight to bed afterwards. Your mind will still be “going round and round”—thinking too much. Do something else, maybe walk or get exercise. Choose something that will relax you, and make you think of other things.
If you feel bad, talk to someone about your worries. But don’t be too relaxed! Some stress over exams makes you work hard for them.
小題1:How does the writer feel about exams?
A.Excited.B.Bored.C.Worried.D.Surprised.
小題2:Why are the students afraid of exams?
A.Because they are afraid of failing.
B.Because they want to get full marks.
C.Because exams are usually hard.
D.Because their teachers will be angry at their bad grades.
小題3:Which is NOT mentioned in the passage?
A.Good students don’t wait until the week before an exam.
B.Start planning and working for each exam early.
C.If you don’t know how to work for an exam, ask the teacher about it.
D.You should sleep well before the exam.
小題4:According to the passage, if you feel bad, you’d better _____.
A.take a short rest
B.tell someone about your worries
C.walk or get exercise
D.keep busy working and forget your worries

查看答案和解析>>

科目:初中英語 來源:不詳 題型:閱讀理解

完形填空(10分)閱讀下列短文,選擇可以填入空白處的最佳選項(xiàng)。
Water, it’s a problem for the whole world. A bottle (瓶) of water may not seem like much to us,  1  it can help the people who live in drought-hit (遭受旱災(zāi)的) areas in China.
  In the past few months, many places in southwest China have 2     a serious drought. There has been very little  3 since last autumn. More than 20 million people are 4   trouble finding safe drinking water.
  After learning about the drought, many people around the country helped by  5   away water, money and other resources (資源) to the people there.
  Last week, the Young Pioneers and the Communist Youth League in China called on (號(hào)召) each student to give one bottle of water to the drought-hit area. In Xi’an, 900 students bought over 1000 bottles of water 6     their pocket money. They also wrote their  7   on the bottles. “I hope you get more rain there. I hope you are happy.”
  A bottle of water isn’t much, but thousands of bottles will be very  8  . The serious drought has also made students  9  the importance of saving water. One student said, “I have decided to take a shower twice a week  10   every day to save water.”
小題1:
A.unlessB.a(chǎn)ndC.butD.because
小題2:
A.boughtB.experiencedC.studied D.missed
小題3:
A.rain B.wind C.snowD.sunshine
小題4:
A.causing B.makingC.havingD.bringing
小題5:
A.drinkingB.givingC.gettingD.collecting
小題6:
A.ByB.in C.forD.With
小題7:
A.plansB.notesC.wishes D.dates
小題8:
A.relaxingB.beautifulC.boringD.helpful
小題9:
A.thinkB.realizeC.missD.regard
小題10:
A.instead B.instead of C.except D.because of

查看答案和解析>>

科目:初中英語 來源:不詳 題型:閱讀理解

Mr White works in an office. He’s very busy and has no time to have a good rest. Every evening, when he comes back from his office, he’s always tired and wants to go to bed early. But his wife often has a lot of interesting things to tell him after dinner. She doesn’t stop talking until she falls asleep (入睡). But it’s usually too late and Mr White has to get up early in the morning when she is still sleeping.
One day Mr White felt terrible and couldn’t go to work. He decided to go to see a doctor. Mrs White went to the hospital with him. Before her husband said what was the matter with him, the woman told the doctor all. The doctor wrote out a prescription (處方). When Mrs White took the medicine to the doctor’s room, the doctor said to her, “The bottle of medicine is for your husband and the pills (藥片) are for you. ”
“For me?” the woman said in surprise. “I’m fine. I don’t need any medicine!”
“I don’t think so, madam,” said the doctor. “They are sleeping pills. Your husband will be all right soon if you take them. ”
小題1:Mr White ______.
A.has time to have a good sleep
B.is busy but he can have a good sleep
C.isn’t tired and doesn’t like to go to bed early
D.doesn’t have a good rest
小題2:Mr White’s wife ______ every evening.
A.works lateB.writes things C.keeps talking lateD.watches TV late
小題3:Mr White has to get up when his wife is sleeping in the morning because ______.
A.he can’t fall asleepB.he has to go to work
C.he doesn’t want to sleepD.his wife asks him to get up
小題4:One day Mr White couldn’t go to work because ______.
A.he was illB.his wife was ill
C.his wife didn’t let him goD.he didn’t want to go to work
小題5:The sentence “Your husband will be all right soon if you take them. ” means Mr White will soon be all right if ______.
A.Mr White takes the pills
B.Mr White takes the bottle of medicine
C.Mrs White takes the pills
D.Mrs White stops talking too much at night

查看答案和解析>>

同步練習(xí)冊(cè)答案