It is easy for us to tell who our family members are, but do plants recognize(識別) 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

解析試題分析:這篇文章講的是科學(xué)家通過做實驗,發(fā)現(xiàn)將一種植物與不同種類的植物種植在一起,它會和其他植物競爭養(yǎng)分,將會長的更好,如果單獨種植的話,則會分享資源,而不競爭。
【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.在他們的實驗中,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,第二自然段對這個說法進(jìn)行了一項有關(guān)jewelweeds鳳仙花的研究,所以在此是為了點明主題。
【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,它就會比單獨種植時生長出更多的葉子。故可知,答案選C
【小題4】主旨題。這篇文章講的是科學(xué)家通過實驗,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.
考點:科普類說明文
點評:本文較難,科技類的文體是比較繁瑣的,因為專有名詞較多。學(xué)生在解答這類題目時,首先對文章有大致的掌握,對于文章一遍沒有看懂時,可以先看題目,按照文章題目的提示,再在文章中找出相對應(yīng)的地方,然后仔細(xì)分析文章的上下文,同時對于專有名詞可以用筆畫出,通過多個地方的比較就可以猜出意思了。

練習(xí)冊系列答案
相關(guān)習(xí)題

科目:初中英語 來源: 題型:

A. Entertainment News
In this section all kinds of news about movies, songs and pop stars are available (可找到的).
B.  Advertisement Section
Here are advertisements of different products, such as food, latest books, and sporls machines, etc.
C. Reading Section
In this part, we will introduce some hot traveling places to you. Some safety tips during journeys are also offered.
D. International News
Here is news about the events that happened all over the world.
E. Sports News
Important sports events are broadcast (傳播)here. And we often interview some good players.
F.  Health Section
Winter is coming and it is easy to get ill. If you want to know how to keep away from diseases, you should pay attention to this section.
Match the information according to what you read.
【小題1】   Mike cares about sports events and how the sports players are now.
【小題2】Mr. Brown is interested in reading. He wants to know what kinds of new books have come out and where to buy them.
【小題3】   Zhang Peng is really a film fan. Recently he would like to know what new movies are like and some information about Jackie Chan.
【小題4】Lana's father is working abroad (國外)in Libya. A war (戰(zhàn)爭)broke out there, so she is rather worried about the situation in Libya.
【小題5】Lucy is in poor health. She is so anxious to know how to keep fit.

查看答案和解析>>

科目:初中英語 來源:2012-2013學(xué)年廣東執(zhí)信中學(xué)八年級上學(xué)期期中考試英語試卷(帶解析) 題型:完型填空


We are all busy talking about using the Internet, but how many of us know the history of the Internet?
Many people are ___36___ when they find that the Internet was set up in the 1960s. At that time, computers ___37___ large and expensive. Computer networks didn’t work well. If one computer in the network ___38___ down, the whole network stopped. ___39___ a new network system(系統(tǒng))had to be set up. It should be ___40___ to be used by many different computers. If part of the network was not working, ___41___ could be sent through another part. In this way computer network system would keep on ___42___ all the time.
At first the Internet was only used by the government, but in the early 1970s, universities, hospitals and banks were allowed to use it too. However, computers were still very expensive and the Internet was difficult to use. By the start of the 1990s, computers became cheaper and ___43___ to use. Scientists had also developed software that made “surfing”(瀏覽)the Internet more convenient.
Today it is easy to get on-line and it is said that millions of people use the Internet every day. ___44___ e-mail is more and more popular among students. The Internet has now become one of ___45___ parts of people’s life.

【小題1】
A.surpriseB.surprisingC.surprisedD.surprises
【小題2】
A.isB.a(chǎn)reC.wasD.were
【小題3】
A.breakB.breaksC.brokeD.would break
【小題4】
A.BecauseB.SoC.ButD.However
【小題5】
A.good enoughB.well enoughC.enough goodD.enough well
【小題6】
A.informationB.informationsC.a(chǎn)n informationD.the informations
【小題7】
A.workB.to workC.workingD.worked
【小題8】
A.easyB.easilyC.more easilyD.easier
【小題9】
A.SendB.SendingC.To be sentD.Sent
【小題10】
A.importantB.more importantC.most importantD.the most important

查看答案和解析>>

科目:初中英語 來源:2013屆浙江省杭州市綠城育華中學(xué)九年級12月月考英語試卷(帶解析) 題型:閱讀理解

The expression “down to earth” means being open and honest. It is easy to get on with some one who is down to earth. A down-to-earth person is the opposite of someone who acts important or proud.
Down-to-earth people could be important members of society. But they do not consider themselves to be better than others who are less important. A person who is filled with his own importance and pride is said to“ have his nose in the air”.
Americans use another expression that is similar in some ways to down to earth. The expression is“ both feet on the ground”. Someone with both feet on the ground is a person with a good understanding of reality. He may have dreams, but he does not allow them to have influence on his understanding of what is real.
The opposite kind of person is one who “has his head in the clouds”. Someone with his head in the clouds is a person whose mind is not on what is happening in real life. Such a person may be called a day-dreamer.
When we have both our feet on the ground, and when we are down to earth, we do not have our noses in the air. We act honestly and openly to others. Our lives are like the ground below us---solid and strong.
【小題1】A down-to-earth person could be _____.

A.social and proudB.good and opposite
C.real and important D.strong and changeable
【小題2】The expression “has one’s nose in the air” means ______.
A.揚眉吐氣B.目中無人C.瞻前顧后D.裝模作樣
【小題3】If you only consider your own importance, _____.
A.you’ll think you are better than others
B.your life will be like the solid and strong ground
C.you’ll be hated by down-to-earth people
D.your life will be filled with love.
【小題4】If you want to understand what is real in life, you have to ____.
A.get along with other people easily
B.learn from those who are down to earth
C.be a good dreamer with quick mind
D.have your head in the clouds.
【小題5】This passage mainly talks about ______.
A.the use of some expressions
B.dreams and achievements
C.the lifestyle of honest people
D.honest and understanding

查看答案和解析>>

科目:初中英語 來源:2011屆浙江省臺州市路橋區(qū)八校初三第一次模擬考試英語試卷(帶解析) 題型:閱讀理解

Minzu Hotel Beijing

Star Rating:
Address:51 Fuxingmennei Avenue, Xicheng District, Beijing

On the West Chang An Street, Minzu Hotel Beijing is next to the Xidan Business Center. 2km to Tiananmen Square, 5.5km to Beijing Railway Station, 30km to Beijing International Airport.
Starting in 2005, the hotel is now with both western and Chinese style best services. It is a best home for visitors to Beijing. It has 507 modern new rooms, the restaurants there can serve different styles(風(fēng)格) of food and it has many good meeting halls.
Today’s Low Price: RMB 528 for a standard(標(biāo)準(zhǔn)的) room.
You can pay with    
If you want to book a room, please call:010-66668188
【小題1】Where is the hotel?
A.In Minzu.
B.In Beijing.
C.Near a restaurant.
D.Between the railway station and the airport.
【小題2】The hotel is the nearest to ________.
A.Tian’anmen Square
B.Beijing Railway Station
C.Xidan Business Center
D.Beijing International Airport
【小題3】Why is it a best home for visitors?
A.It is near a shopping center.
B.It is not so expensive.
C.It is easy to go out from.
D.All the above.

查看答案和解析>>

科目:初中英語 來源:2013屆浙江杭州余杭區(qū)星橋中學(xué)初三下期階段性測試英語卷(帶解析) 題型:閱讀理解

Now I know that we black people are much more likely to have high blood pressure and diabetes (糖尿病) than white people. And they often lead to heart attacks and other untreated diseases. For example, black people are three to four times more likely than white people to have high blood pressure and twice as likely as the white population to die of a stroke (中風(fēng)).
New research has found out the surprisingly high levels of salt in many of black people’s favorite meals. I stopped putting extra salt in my food at the table long ago and I try to cut down on the salt. I use in cooking. The suggested daily level of salt for adults is 6 grams. It is easy to see that if you try not to eat too many processed (加工過的) foods and use salt in your cooking within the limit, you won’t reach more than the daily level.
The research showed how much salt there is in some foods that we buy from restaurants and takeaways. An average salad with rice and peas has 6.2 grams of salt. This is more salt than you are supposed to eat for the whole day.
A researcher talked about the importance of home cooking rather than take-outs. At home, he pointed out, not only can you hold control of the salt bottle, but also you can create tasty food which is low on salt. The researcher later provided curry goat and rice and peas. They were low on salt, but completely delicious.
I do not suppose Jamaicans are going to stop buying takeaways soon. But if you suffer from high blood pressure, it is probably better not to buy them often.
【小題1】The underlined word “they” in Paragraph 1 refers to _______.

A.white peopleB.black people
C.untreated diseasesD.high blood pressure and diabetes
【小題2】What has the new research found out according to Paragraph 2?
A.Black people take in too much salt.
B.Black people’s meals are very special.
C.Processed foods have too much salt in them.
D.6 grams of salt per day is enough for an adult.
【小題3】What would the writer probably suggest black people do?
A.Order no salad in a restaurant.B.Take in no salt for several days.
C.Stop cooking their favorite meals.D.Eat less takeaways.
【小題4】The researcher provided curry goat and rice and peas in order to _______.
A.thank those who came to his home for his research
B.let people know that eating less salt makes one healthier
C.show that tasty food with less salt can be made at home
D.prove the less salt the food has the more delicious it is
【小題5】What would be the best title for this passage?
A.Watch the saltB.Take care, black people
C.Say no to takeawaysD.Say no to high blood pressure

查看答案和解析>>

同步練習(xí)冊答案