Although it has been revealed in recent years that plants are capable of seeing, hearing and smelling, they are still usually thought of as silent. But now, for the first time, they have been recorded making ultrasonic cries when stressed, which researchers say could open up a new field of precision agriculture where farmers listen for water-starved crops.
Itzhak Khait and his colleagues at Tel Aviv University in Israel found that tomato and tobacco plants made cries at frequencies humans cannot hear when stressed by a lack of water or when their stem is cut.
Microphones placed 10 centimetres from the plants picked up sounds in the ultrasonic range of 20 to 100 kilohertz, which the team says insects and some mammals would be capable of hearing and responding to from as far as 5 metres away. A moth may decide against laying eggs on a plant that sounds water-stressed, the researchers suggest. Plants could even hear that other plants are short of water and react accordingly, they speculate.
On average, drought-stressed tomato plants made 35 sounds an hour, while tobacco plants made 11. When plant stems were cut, tomato plants made an average of 25 sounds in the following hour, and tobacco plants 15. Unstressed plants produced fewer than one sound per hour, on average.
It is even possible to distinguish between the sounds to know what the stress is. The researchers trained a machine-learning model to discriminate between the plants’ sounds and the wind, rain and other noises of the greenhouse, correctly identifying in most cases whether the stress was caused by dryness or a cut, based on the sound’s intensity and frequency. Water-hungry tobacco appears to make louder sounds than cut tobacco, for example.
Enabling farmers to listen for water-stressed plants could “open a new direction in the field of precision agriculture”, the researchers suggest. They add that such an ability will be increasingly important as climate change exposes more areas to drought.
“The suggestion that the sounds that drought-stressed plants make could be used in precision agriculture seems feasible if it is not too costly to set up the recording in a field situation,” says Anne Visscher at the Royal Botanic Gardens, Kew, in the UK.
She warns that the results can’t yet be broadened out to other stresses, such as salt or temperature, because these may not lead to sounds. In addition, there have been no experiments to show whether moths or any other animal can hear and respond to the sounds the plants make, so that idea remains speculative（推测的）for now, she says.
1.The experiment by researchers at Tel Aviv University shows that_______.
A.tobacco plants make louder sounds than tomato plants when hurt
B.water-hungry tomato plants are more sensible than tobacco plants
C.unstressed plants produced sounds of laughter when being watered
D.plants respond to the sounds the plants make and protect themselves
2.What is Anne Visscher’s attitude towards the finding of the experiment?
A.Appreciative B.Doubtful
C.Cautious D.Optimistic
3.It can be learnt from the research that ________.
A.greenhouse effects can be avoided
B.soil condition can be adjusted in time.
C.plant condition can be diagnosed faster.
D.insects can be detected and removed easily.
4.What is the best title for the article?
A.Plants Get Stressed Just Like Us
B.Plants Scream in Presence of Stress
C.Sounds of Plants Detected Far Away
D.Sounds of Plants Break Farmers’ Hearts
THE OLD FISHERMAN
Our house was directly across a popular hospital. We rented the upstairs rooms to outpatients at the clinic. One summer evening, there was a knock at the door. I opened it to see a truly awful looking man, his face lopsided from swelling, red and raw. He told me he’d been hunting for a room since noon but he had no success. “I guess it’s my face. I know it looks terrible, but my doctor says with a few more treatments…”
For a moment I hesitated, but his next words convinced me: “I could sleep in this rocking chair on the porch. My bus leaves early in the morning.” I told him we would find him a bed, but to rest on the porch. It didn’t take a long time to see that this old man had an oversized heart crowded into that tiny body. He told me he fished for a living to support his daughter, her five children, and her husband, who was hopelessly crippled from a back injury. He didn’t tell it by way of complaint. He was grateful that no pain accompanied his disease.
At bedtime, we put a camp cot in the children’s room for him. When I got up in the morning, the bed linens were neatly folded and the little man was out on the porch. Before he left for his bus, haltingly, he said, “Could I please come back and stay the next time I have a treatment? I can sleep fine in a chair.” He paused a moment and then added, “Your children made me feel at home. Grownups are bothered by my face, but children don’t seem to mind.” I told him he was welcome to come again.
In the years he came to stay overnight with us. There was never a time that he did not bring us fish or oysters or vegetables from his garden. When I received these little remembrances, I often thought of a comment our next-door neighbor made after he left that first morning. “You can lose roomers by putting up such people!”
Maybe we did lose roomers once or twice. But oh! If only they could have known him, perhaps their illnesses would have been easier to bear. I know our family always will be grateful to have known him; from him we learned what it was to accept the bad without complaint and the good with gratitude.
1.When the old fisherman stayed overnight, the author’s children ________________.
A.were bothered B.were terrified
C.felt normal D.felt at home
2.Which of the following statement is true about the fisherman?
A.He is both tall and strong.
B.He has five grandchildren.
C.He is pessimistic about life.
D.He suffers from a back injury.
3.The old fisherman gave the author fishes and oysters because he________.
A.wanted the author to buy them.
B.wanted to pay the rent with them.
C.had fished too many fishes and oysters.
D.wanted to show his thankfulness to the author.
4.What can we learn from the story?
A.Never judge a book by its cover.
B.Little strokes fell great oaks.
C.Stay positive, stay grateful.
D.Honesty is the best policy.
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1.What is the main purpose of the passage?
A.To offer medical help to patients
B.To look for experienced researchers
C.To introduce new research programs
D.To recruit volunteers for research projects
2.The goal of OVG is to _______.
A.carry out clinical trials
B.produce vaccines against viruses
C.learn more about the immune system
D.study the occurrence of infectious diseases
3.You can finish the experiment on your home PC if you join __________.
A.Oxford Vaccine Group
B.Insomnia research group
C.Oxford Experimental lab
D.Brain Scanning study group
“Hi!” Steller shouted. “I’m driving around giving free haircuts. Do you want one right now?”
The man looked to be in his 60s, heavyset and missing a few teeth. “Actually,” he said, “I have a wedding to go to. I was really _______ to get a haircut.”
The man, named Edward, _______ sat on Steller’s red chair. She began to trim his curly graying hair. Then he began to tell her about his childhood, about moving here to be closer to his adult children, and how he still talks to his mom every day. After the haircut, Edward looked in a mirror, exclaiming “I look _______! I’ll remember to put my _______ in next time. I look better with teeth!”
To date, Steller has given 30 or so such haircuts. These clients all live on the margins (边缘), and she is keenly aware of the _______ of her clean-up job. “It’s more than a haircut,” she says. “I want it to be a gateway—to show value and _______.”
Steller knows that a haircut can change a life. As a teen, she suffered from a(n) _______ which was so severe that her hair _______ drastically. Seeing this, her mother arranged for Steller’s first professional haircut. “To sit down and have somebody talk to me like a person and not just an illness, it helped me feel _______ about and less alone,” she says.
After that, Steller decided to have her own salon so she could help people feel the ________ she’d felt that day. Not long after finishing cosmetology (美容术) school, she began her Red Chair Project, ________ out to people on the streets. Although she can’t ________ their problems by giving free haircuts, she believes it might help them feel less ________ for a moment.
Steller listens to people’s ________ of loss and struggle to get back on their feet. The attention apparently ________. When she was cutting a woman’s hair one day, someone drove by and yelled, “You look amazing!” The woman in the chair beamed. “I’m not ________,” she exclaimed. “I thought I was invisible. Look, people see me!”
A Branch of the Red Chair Project is the Steller Kindness Project, in which people who ________ acts of kindness are invited for a free makeover (美容) at Steller’s salon. In exchange, they tell their stories, which Steller ________ on her website. Her hope is that by reading about kind acts, others will be ________ to spread their own.
So far, it’s working. And it all began with a(n) ________ in simple acts of kindness, such as a free haircut.
1.A.hoping B.learning C.promising D.hesitating
2.A.freely B.gladly C.patiently D.voluntarily
3.A.fit B.ugly C.good D.silly
4.A.feet B.hand C.heart D.teeth
5.A.energy B.force C.length D.power
6.A.reward B.respect C.sympathy D.determination
7.A.attack B.threat C.accident D.disease
8.A.thinned B.loosened C.whitened D.shortened
9.A.cared B.worried C.known D.thought
10.A.use B.way C.need D.reason
11.A.running B.calling C.reaching D.pointing
12.A.fix B.face C.raise D.present
13.A.afraid B.alone C.annoyed D.ashamed
14.A.complaints B.explanations C.desires D.stories
15.A.disappears B.grows C.works D.spreads
16.A.innocent B.invisible C.unimportant D.uncommon
17.A.appreciate B.discover C.commit D.witness
18.A.creates B.enjoys C.sells D.shares
19.A.urged B.allowed C.inspired D.persuaded
20.A.belief B.trust C.investment D.pleasure
阅读下列短文，根据短文内容填空。在未给提示词的空白处仅填写1个适当的单词，在给出提示词的空白处用括号内所给词的正确形式填空。
I honestly believe there’s a danger that the more connected we are, the more isolated we feel. I don’t think this is such an issue for my generation who’ve lived 1. technology for so long. We know how to be alone and, more importantly, we know that it’s OK to be alone. 2. the under 20s are another kettle of fish. They’re so busy that they never experience the feeling of solitude and run the risk of not learning how to enjoy their own company. In addition, they’re learning conversation through messages that can 3. (edit) and changed at the expense of learning the art of real conversation in real time with the person in front of you .
阅读下列短文，根据短文内容填空。在未给提示词的空白处仅填写1个适当的单词，在给出提示词的空白处用括号内所给词的正确形式填空。
It’s a popular 1. (believe) that fish can’t remember anything for longer than seven seconds. It may seem sad to think that they don’t remember what they’ve eaten or 2. they’ve been, and they don’t recognize you or any of their friends —every moment in their lives would be like seeing the world for the first time. But don’t be so quick to feel sorry for them. A recent study 3. (find) that fish have much 4. (good) memories than we used to think. In fact, certain species of fish can even remember events from as long as 12 days ago.
