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Plants can’t communicate by moving or making sounds, as most animals do. Instead, plants Produce volatile compounds, chemicals that easily change from a liquid to a gas. A flower’s sweet smell, for example, comes from volatile compounds that the plant produces to attract insects such as Bugs and bees.
Plants can also detect volatile compounds produced by other plants. A tree under attack by Hungry insets, for instance, may give off volatile compounds that let other trees know about the Attack. In response, the other trees may send off chemicals to keep the bugs away ——or even  Chemicals that attract the bugs’ natural enemies.
Now scientists have created a quick way to understand what plants are saying: a chemical Sensor(传感器)called an electronic nose. The “e-nose” can tell compounds that crop plants make When they’re attacked Scientists say the e-nose could help quickly detect whether plants are being Eaten by insects. But today the only way to detect such insects is to visually inspect individual Plants. This is a challenging task for managers of greenhouses, enclosed gardens than can house Thousands of plants.
The research team worked with an e-nose than recognizes volatile compounds. Inside the device, 13 sensors chemically react with volatile compounds Based on these interactions, the e-nose gives off electronic signals that the scientists analyze using computer software.
To test the nose, the team presented it with healthy leaves from cucumber, pepper and tomato plants, all common greenhouse crops. Then scientists collected samples of air around damaged leaves from each type of crop, These plants had been damaged by insects, or by scientists who made holes in the leaves with a hole punch(打孔器). The e-nose, it turns out, could identify healthy cucumber, pepper and tomato plants based on The volatile compounds they produce, It could also identify tomato leaves that had been damaged. But even more impressive, the device could tell which type of damage ---- by insects or with a hole Punch ---- had been done to the tomato leaves.
With some fine-tuning, a device like the e-nose could one day be used in greenhouses to quickly spot harmful bugs, the researchers say. A device like this could also be used to identify fruits that are perfectly ripe and ready to pick and eat, says Natalia Dudareva, a biochemist at Purdue University in West Lafayette, Ind. who studies smells of flowers and plants. Hopefully, scientists believe, the device could bring large benefits to greenhouse managers in the near future.
We learn from the text that plants communicate with each other by____.

A.making some sounds B.waving their leaves
C.producing some chemicals D.sending out electronic signals

What did the scientists do to find out if the e-nose worked?

A.They presented it with all common crops.
B.They fixed 13 sensors inside the device.
C.They collected different damaged leaves.
D.They made tests on damaged and healthy leaves.

According to the writer, the most amazing thing about the e-nose is that it can___.

A.pick out ripe fruits
B.spot the insects quickly
C.distinguish different damages to the leaves
D.recognize unhealthy tomato leaves

We can infer from the last paragraph that the e-nose_____.

A.is unable to tell the smell of flowers
B.is not yet used in greenhouses
C.is designed by scientists at Purdue
D.is helpful in killing harmful insects
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It’s never a real problem for us when the weather gets cold. We can put on more clothes, stay next to a fireplace, turn on the air conditioner or simply travel to a warmer city to spend the winter – people have many different ways of dealing with the cold.
But things are not as easy for plants. Unlike humans, plants can’t move to escape the cold or generate heat ( 发热) to keep themselves warm. So how do they manage to survive the freezing winter?
It turns out that plants have their own strategies (策略) too, said a study published on Dec 22 in the journal Nature.
According to researcher Amy Zanne of George Washington University, US, the cold is a big challenge for plants. Their living tissues (活组织) can be damaged when they freeze. “It’s like a plant’s equivalent to frostbite ( 相当于冻疮),” Zanne told Science Daily. Also, the process of freezing and thawing (解冻) can cause air bubbles (气泡) to form in the plant’s water transport system. “If enough of these air bubbles come together as water thaws they can block the flow of water from the roots to the leaves and kill the plant,” she explained.
To live through cold weather, plants have developed three traits (特性) , according to the study. Some plants, such as oak trees(橡树), avoid freezing damage by dropping their leaves before the winter chill sets in – effectively shutting off the flow of water between roots and leaves – and growing new leaves and water transport cells when the warm spring returns.
Other plants, pine trees(松树) for example, protect themselves by narrowing their water transport cells, which makes it easier for cells to travel among air bubbles.
The third strategy is also the most extreme – some plants die on the ground in winter and start growing as new plants from seeds when conditions get warmer.
However, the study also found that these smart strategies were developed very slowly – over millions
of years of evolution ( 进化). This leads scientists to worry that plants may not be able to deal with human-caused climate change, which has only started occurring over the past few decades.
Scientists are hoping that this study can help people find possible ways to save plants from the threat
of climate change.
What is the article mainly about?

A.Why plants are not afraid of the winter chill.
B.The ways that plants survive cold weather.
C.Changes in plants’ water transport system in winter.
D.How plants evolve to keep up with climate change.

According to the article, if a plant freezes in the winter, ______.

A.it produces more living tissues to stay alive
B.its leaves quickly fall out and its roots begin to die
C.lots of air bubbles form in its water transport system
D.its water transport system could be blocked in the spring

What are scientists worried about when it comes to plants according to the article?

A.Plants may not be able to adapt to the increasingly cold climate.
B.Human activities might have a great impact on the pace of plants’ evolution.
C.Plants may not be able to evolve fast enough to adapt to human-caused climate change.
D.The strategies plants develop are not good enough to protect them against cold.

The old man walked with a cane (拐杖) slowly into the restaurant. His poor jacket, patched (打补丁的) trousers, and worn-out shoes made him stand out from the usual Saturday morning breakfast crowd.
He walked toward a table by the window. A young waitress watched him and ran over to him, saying, “Here, Sir. Let me give you a hand with that chair.”
Without a word, he smiled and nodded a thank you. She pulled the chair away from the table. Supporting him with one arm, she helped him move in front of the chair, and get comfortably seated. Then she pushed the table up close to him, and leaned his cane against the table where he could reach it.
In a soft, clear voice he said, “Thank you, Miss.”
“You’re welcome, Sir.” She replied. “My name is Mary. I’ll be back in a moment. If you need anything, just wave at me.”
After he had finished a hearty meal of pancakes, bacon, and hot lemon tea, Mary brought him the change, helping him up from his chair and out from behind the table. She handed him his cane, and walked with him to the front door. Holding the door open for him, she said, “Come back and see us, Sir!”
He nodded a thank you and said softly with a smile, “You are very kind!”
When Mary went to clean his table, she was shocked. Under his plate she found a business card and a note written on the napkin, under which was a $ 100 bill.
The note on the napkin read, “Dear Mary, I respect you very much, and you respect yourself, too. It shows by the way you treat others. You have found the secret of happiness. Your kind gestures will shine through those who meet you.”
The man she had served was the owner of the restaurant. This was the first time that she, or any of his employees, had seen him in person.
Mary ran over to the old man because _____.

A.the old man was the boss of the restaurant
B.she was worried that the old man might cause trouble to the restaurant
C.she saw the old man had some difficulty moving and taking a seat
D.the old man had asked her to wait on him

The man came to the restaurant ______.

A.to have breakfast
B.to see his employees
C.to find out how his restaurant was working
D.to see how Mary served customers

The words the man left on the napkin suggested that _____.

A.respecting others means respecting oneself
B.serving others is a respectable job
C.Mary would get a rise as a result of her kindness
D.Mary’s kind service would bring in more money for her

Which of the following titles goes best with the story?

A.A kind- hearted Girl
B.Shining Kindness
C.Kindness Means Opportunities
D.A Special Customer

We are naturally drawn to friends and colleagues with familiar voices, scientists have found.People prefer those who have a similar accent,intonation and tone of voice to themselves , they discovered.
Previous research has focused on how masculine or feminine a voice sounds.Men with deeper voices and women with slightly higher voices were thought to sound more attractive,because they suggest a bigger or a smaller body.
But the new study,published by a linguistics(语言学)expert in Canada,suggests there is a
more complex mechanism(机制)at play.Dr Molly Babel, from the University of British Columbia in Canada, said,“The voice is an amazingly flexible(灵活的)tool that we use to construct our identity.Very few things in our voices are changeless,so we felt that our preferences had to be about more than a person’s shape and size.’’
She recorded 30 volunteers’ voices and asked each to rate the others’ attractiveness on a scale of one to nine.Each participant was from western America,with similar accents.The people we assessed were all in the same dialect group,but they showed that dialect to different degrees.
“We seem to like people who sound like we sound,we like people who fit within what we know,”Dr Babel said.She also found that breathy voices in women-typified by the famous American actress Marilyn Monroe-were seen as more attractive.
The breathy tone,caused by younger and thinner vocal cords(声带),implied youthfulness
and health A creaky voice,suggesting a person has a cold,is tired or smokes,was seen as unattractive.The participants preferred men who spoke with a shorter average word length and deeper voices.
The linguist,whose work is published in the journal PLOS One,said,“Once you’re outside of a certain range of familiarity,novel and exotic sounding voices might become more attractive.We also have to keep in mind we find some accents more preferable than others because of social fixed ideas.”
In terms of voice preferences,the new findings highlight_______.

A.body size and shape B.shorter word length
C.thicker vocal cords D.the same social groups

Dr. Molly Babel mentions Marilyn Monroe in order to________.

A.evaluate a creaky voice
B.explain her new findings
C.challenge previous research
D.promote the actress’s reputation

According to the passage,who would most probably have a creaky voice?

A.An old lady with a silvery voice.
B.A young lady with a thin voice.
C.A deep-voiced man with a dry throat.
D.A little man with a quiet and gentle voice.

What can be inferred from the last paragraph?

A.People favor familiar accents when in a new place.
B.People might have a preference for different accents.
C.Voice preferences have no link to long-held belief.
D.Voice preferences are influenced by sex differences.

The main purpose of the passage is to________.

A.encourage men to use shorter words and talk less
B.inform readers of the findings of voices
C.argue against women’s breathy way of speaking
D.compare male voices with female voices

BERLIN (Reuters)—Germany’s postal service has announced plans to explore improved service and help protect the environment by getting “fetch friends”—ordinary people traveling across cities—to deliver parcels on their way.
It is hoped that the move, which will be tested in the coming months, might lessen traffic in inner cities and reduce CO2 emissions(排放). This should help DHL, a division of the German postal service, reach its target of improving the company’s carbon efficiency by 30 percent before 2020.
“As the world’s biggest logistics(物流) provider, we recognize a special responsibility to reduce the impact on the environment as much as possible,” said Frank Appel, Chief Executive Officer of Deutsche Post DHL, in a statement referring to a variety of measures being considered.
The “fetch friends” find out online about parcels that need delivering to people who live or work along the way that they are planning to travel through the city. They then select the ones that they want to take.
Codes(编码) sent to their mobile phones tell the volunteers where to pick the packages up. Parcels can be taken part of the way or passed on to another volunteer but all volunteers need to have the right code on their mobile phone so the track and trace system can be updated.
Logistics companies will be responsible for looking after the operation to make sure that the privacy of post is respected.
It’s hoped that this could be done using mobile phones but DHL says it recognizes that some security issues remain to be worked out.
According to the passage, the “fetch friend” program ________.

A.has been tested for months
B.aims to reduce the cost of the service
C.employs environmentalists to help with deliveries
D.encourages ordinary people to help cut the carbon footprint

Which of the following statements is TRUE of DHL?

A.It belongs to the Germany’s postal service.
B.It has the most up-to-date tracking system in Germany.
C.It has succeeded in improving its carbon efficiency by 30%.
D.It has designed many measures to improve its service speed.

What may be a problem with the new service according to the article?

A.Volunteers’ not allowing to select parcels.
B.The wrong codes in the mobile phones.
C.The possibility that parcels could be opened on the way.
D.Parcels’ being taken to the destination by a single volunteer.

What might be the best Title for the best passage?

A.New Challenges for the Postal Service
B.A Greener Way to Deliver Parcels
C.Solutions for Global Warming
D.Statements from DHL

A culture’s values can be mirrored by its humor.Humor has been evaluated by many great minds such as Thomas Hobbes,who,in“On Nature”,disliked humor,“Laughter is nothing else but sudden glory arising from sudden thought of feeling far better than others.”He thought humor to be a negative quality of human narrow-mindedness.
However, Mordechai Gordon,Ph. D of Education,insists,“Humor allows us to view the
world from an angle that is amusing rather than serious.”1 agree with Gordon.Learning to look
at the world through humor is important.
In the United States,every four years an election occurs.Without humor as a way to express their feelings,how else would Americans keep from clawing their eyes out and going the
way of lemming? Television shows like“The Daily Show”have become important parts of American culture.They are mothering the masses by metaphorically(隐喻地) airplane-ing politics into our mouths.They make politics fun.
Of course, politics is only one type of humor.Social humor helps people through the twists
and turns of the human condition.American pop culture promotes an unhealthy self image.On the topic of self-image,Hari Kondabolu stands out.He has a joke about the popular musical group“The Pussycat Dolls”,describing their hit song“Don't Cha”as a negative representation of women.He points out an obvious offence in American culture.
A study from Loyola University of Maryland has shown that humor is one determining factor for selecting a mating partner.Amongst other things,mates look for an outstanding funny
bone in a potential partner.
Of course,humor is not always used for good purposes.Humor can be linked to vulgarity
(粗俗)and racism,but,like everything else,it has potential to unite human beings by allowing
us to laugh at ourselves,our failures and our connection with one another.
Though 1ife may seem tough and depressing at times,all I have to do is look in the mirror at my increased wrinkles(皱纹) to know that there is a comedy out there that even Chaplin wasn’t
aware of.
With that in mind,remember to laugh with humanity and sometimes at humanity.
Hobbes believes that humor__________.

A.was only a way to laugh at others to make oneself feel better
B.resulted in narrow-mindedness of human beings
C.had the power to mirror personal glory and national values
D.was for people to view the world from another angle

What is the author’s attitude towards political humor?

A.Worried B.Disappointed
C.Curious D.Appreciative

The fourth paragraph is developed mainly__________.

A.by example B.by process
C.by comparison D.by classification

What can we learn from the last two paragraphs?

A.Chaplin wasn’t aware of being laughed at
B.The author feels helpless and sad about getting older
C.Never be the one who laughs at other people
D.The author is determined to face life with a sense of humor.

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