“A beautiful field of flowers can be a rather noisy place. It’s just that we can’t hear the sounds.” Scientists at Tel Aviv University have conducted a six-year experiment, proving that plants make noise in certain stressful situations.
Plants produce a high frequency (频率) clicking sound, and when short of water, or damaged, the clicks become far more regular. They also made different sounds, depending on whether they were thirsty or injured. “Each plant and each type of stress is related to a specific sound,” said Professor Lilach Hadany, who led the research study.
Focusing particularly on tomatoes, wheat and corn, the plants were placed in a soundproof(隔音的)room and recorded by microphones. Some plants were starved of water, others cut, and a control group was left undamaged. The researchers used an algorithm (算法) to separate the noises, suecessfully telling the difference between the sounds depending on whether they were dry or cut. The algorithm did this in a greenhouse setting which included far more surrounding sounds, but it was still able to recognize the particular cries for help of the plants.
On average, the human ear can hear sounds up to around 20kHz, while the sounds produced by plants are in the 40-80kHz region, far beyond our hearing. “The sounds made by plants can’t be heard by humans but can probably be heard by various animals, such as bats, mice and insects,” Hadany tells us. Though this has yet to be proven, it’s possible that these creatures use this information to choose which plants to eat.
A study led by Reda Hassanien of China Agriculural University in Beijing years ago, also proved that plants reacted to sound waves, with some plants greatly increasing their yield. While evidence shows that plants can react to sounds, there’s no evidence today that they can actually hear them.
1. What can we know from the six-year experiment?| A．Plants of different types make the sound of the same frequeney. |
| B．Plants produce more regular sound in certain stressful situations. |
| C．Plants make sounds with a much lower frequency when stressed. |
| D．Plants make the sound of the same frequeney whatever the situation. |
| A．To record the sounds. | B．To control the sounds. |
| C．To produce the sounds. | D．To identify the sounds. |
| A．Plants can hear each other’s cry for help. |
| B．Animals can hear the sounds made by plants. |
| C．Plants can make sounds and respond to sound waves. |
| D．Animals decide what to eat based on the sounds plants make. |
| A．Sounds That We Can’t Hear |
| B．Beautiful Songs from Plants |
| C．Plants React to Different Types of Stress |
| D．Plants Talk, Especially When Stressed |
相似题推荐
【推荐1】Growing up in poverty can have long-term negative consequences for children. Now, a study offering unconditional cash to a group of mothers on low incomes in the US is beginning to discover the precise role of parental income in child development. It is the first randomised trial to look at whether a basic income might affect the way a child’s brain develops in this critical period.
We know that the first few years of a child’s life are the most influential for their development. Brain development is particularly rapid in early childhood and therefore more likely to be influenced by the environment.
Studies of children born into families with low incomes have found they tend to have more behavioural problems and are behind their peers when they start school. However, it isn’t clear whether low income directly leads to these outcomes, or whether they are a result of other factors associated with growing up in poverty.
To find out, Kimberly Noble at Columbia University in New York City and her colleagues approached women on low incomes who had just given birth at four sites in the US. The team is measuring several things throughout the study. At each yearly follow-up, children are assessed for measures like sleep quality, developmental milestones, overall health and emotional development. One unique aspect of the study is the use of mobile EEG headsets to monitor the infants’ brain activity in their home environments.
Almost $4 million has been given out through the study so far. Though it is too early to draw full conclusions, some preliminary(初步的) results are already of interest. For example, some of the parents have allowed the researchers to keep track of their transactions(事务). Those in the high-cash group appear to be spending more on books for their children, and spending more time reading together, according to surveys the team conducted. This is potentially good news because reading to infants is known to be good for cognitive development, vocabulary and promoting important bonds between adults and children.
Eventually, the findings could help with policy interventions(干预) to assist children born into poverty, or even to find ways to buffer against the effects of poverty later in life.
1. The passage mainly intends to tell us that ______.| A．the early years of a child’s life are the most influential |
| B．women should earn more to promote children’s development |
| C．money affects brain development in one’s childhood |
| D．comprehensive measures are to be taken to assist the children |
| A．the family can live a carefree life with flip cash |
| B．it helps to offer better environment for the children |
| C．the family can offer the children more nutrition |
| D．it provides more time for the family to get together |
| A．prevent | B．cause |
| C．decline | D．transform |
| A．By doing follow-up researches. | B．By taking randomised trials. |
| C．By giving participants interviews. | D．By making questionnaires. |
【推荐2】Julie boergers, Ph．D a sleep expert from the Bradley Hasbro Children's Research Center, recently led a study connecting later school start times to improved sleep and mood in teens．
"Sleep deprivation is common among teenagers, with potentially serious impacts on mental and physical health, safety and learning.Early high school start times contribute to this problem，"said Boergers."In this study, we looked at whether a delay in school start time would change students' sleep patterns, sleepiness, mood and caffeine(咖啡因)use."
Beorgers' team conducted the School Sleep Habits survey among boarding students attending an independent high school both before and after their school start time was experimentally delayed from 8 to 8:25 a.m.during the winter term.The delay in school start time led to a significant increase (29 minutes)in sleep duration on school nights, with the percentage of students receiving eight or more hours of sleep on a school night jumping from 18 to 44 percent The research found that younger students and those sleeping less at the start of the study were most likely to benefit from the timetable change.Daytime sleepiness, low mood and caffeine use were all significantly reduced after the delay in school start time.The later school start time had no effect on the number of hours students spent doing homework, playing sports or taking part in activities outside class. And once the earlier start time changed back during the spring term, teens reverted(恢复)back to their original levels.
Beorgers said that these findings are important for public policy."The result of this study add to a growing body of research showing important health benefits of later school start times for adolescents, " she said, " and we have students who are more alert(机敏的), happier, better prepared to learn, and aren't dependent on caffeine and energy drinks just to stay awake in class."
1. What does the underlined phrase "this problem" in Paragraph 2 refer to？| A．Lack of sleep. |
| B．Mental health. |
| C．Students' safety. |
| D．Taking energy drinks. |
| A．Students had less time playing sports. |
| B．Young students became sleepier. |
| C．More students slept longer. |
| D．Students got a bad mood. |
| A．It helps form good habits. |
| B．It relates to what students learn. |
| C．It increases students' learning interest. |
| D．It may have an effect on a public policy. |
| A．A science journal. |
| B．A history book. |
| C．A fashion magazine. |
| D．A school yearbook. |
【推荐3】Strangely enough, music is no fun at all for some people. About four percent of the population is what scientists call “amusic”, people who are amusic are born without the ability to recognize or reproduce musical notes. Amusic people often cannot tell the difference between two songs. Amusics can only hear the difference between two notes if they are very far apart on the musical scale.
As a result, songs sound like noise to an amusic. Many amusics compare the sound of music to pieces of metal hitting each other. Life can be hard for amusics. Their inability to enjoy music set them apart from others. It can be difficult for other people to identify with their condition. In fact, most people cannot begin to grasp what it feels like to be amusic. Just going to a restaurant or a shopping mall can be uncomfortable or even painful. That is why many amusics intentionally stay away from places where there is music. However, this can result in withdrawal and social isolation. “I used to hate parties,” says Margaret, a seventy-year-old woman who only recently discovered that she was amusic.
By studying people like Margaret, scientists are finally learning how to identify this unusual condition.
Scientists say that the brains of amusics are different from the brains of people who can appreciate music. The difference is complex, but it doesn’t involve defective hearing. Amusics can understand other nonmusical sounds well. They also have no problems understanding ordinary speech. Scientists compare amusics to people who just can’t see certain colors.
Many amusics are happy when their condition is finally diagnosed. For years, Margaret felt embarrassed about her problem with music. Now she knows that she is not alone. There is a name for her condition. That makes it easier for her to explain. “When people invite me to a concert, I just say, No, thanks, I am amusic,” says Margaret. “I just wish I had learned to say that when I was seventeen and not seventy. ”
1. Which of the following statements is NOT TRUE about amusics?| A．They are born without the ability to recognize musical notes. |
| B．They prefer to make metal noise rather than listen to music. |
| C．They hate music and often keep off places where there is music. |
| D．They are set apart from others as they fail to enjoy music. |
| A．By sort and compare some data. | B．By carrying out a lot of experiments. |
| C．By drawing on research results of others. | D．By studying people with amusic. |
| A．detective | B．acute | C．imperfect | D．artificial |
| A．her problem with amusic had been diagnosed earlier |
| B．she hadn't felt embarrassed about her problem |
| C．her amusic problem could be cured as soon as possible |
| D．there could be a better name for her condition |
【推荐1】Scientists who study insects are troubled now. All across the United States, bees are leaving their hives and never returning. According to the beekeepers across the country, 25 to 40 percent of the bees in the United States have left their hives since last fall. So far, no one can explain why.
Bees play an important role in the production of about one third of the food we eat. A large number of plants not only need people’s care but also need bees that spread pollen from flower to flower. Without this process, a plant can’t produce seeds or fruits.
Now, a group of scientists and beekeepers are trying to find out what has happened. By examining bees’ behavior and health, they hope to find out what has caused the bees’ disappearance and to prevent bees from disappearing in the future.
Some people think the disappearance may be caused by disease. According to Dewey Caron, a researcher at the University of Delaware, the bees have signs of troubled immune systems (免疫系统) inside their bodies. But why would troubled immune systems cause bees to leave their hives? After all, when people are sick, they want to stay at home. Caron guesses that sick bees may have difficulty figuring out where their homes are.
“Another cause may be some chemicals that farmers use to kill unwanted insects on crops.” says Jerry Hayes, who works at the Florida Department of Agriculture.
1. The underlined part “this process” refers to ________.| A．people’s care |
| B．bees’ leaving their hives |
| C．bees’ spreading pollen from flower to flower |
| D．beekeepers’ raising bees |
| A．the use of some chemicals is the cause of the bees disappearance |
| B．sick bees are not able to find where their hives are |
| C．it’s not known yet why a lot of bees are leaving their hives and never returning |
| D．there will be no bees in America in the near future |
| A．Bees,Humans’ Friends |
| B．Scientists Are Interested in Bees |
| C．Why Are Bees Leaving? |
| D．How Do Bees Send out Information? |
| A．science news |
| B．a public advertisement |
| C．a book on advanced technology |
| D．a business report |
【推荐2】An interesting study posted on Facebook recently shows how men and women develop new interests as they mature(成熟).
While women tend to take exercise seriously from the age of 34, men will wait until their 45th birthdays before working hard to get in shape.The average woman spends more time talking about sports, politics, career and money as she gets older.
Women’s interest in books reaches its peak(顶峰) at the age of 22, while that of men does so when they are in their 50s.
Men start to change their focus from the workplace to other things after age 30, while women do not do so until eight years later. Both, however, care most about fashion at age 16.
The research used anonymous(匿名的) data donated by thousands of Facebook users, recording the statuses, ‘likes’ and ‘interests’ they had posted on their profiles.
It found the average woman talks about television most at 44, while men peak much younger, at age 31.
Men are also most likely to see a film in a cinema at age 31, while women go out to see films most when they are only 19.
Men are most interested in travel at 29, women at 27, while women talk most about food and drink at 35, and men at 38.
And if you are middle aged, a safe topic for any audience is the weather, which is a key interest for many as they approach 60.
Stephen Wolfram, the British scientist who carried out the research, says, “It’s almost shocking how much this tells us about the changes of people’s typical interests. People talk less about video games as they get older, and more about politics.”
1. When do women love books best?| A．At the age of 50. | B．At the age of 22. |
| C．At the age of 30. | D．At the age of 15. |
| A．gain more and more weight | B．do more exercise |
| C．be less interested in their jobs | D．pay more attention to their appearance |
| A．Getting in shape. | B．Going to the cinema. |
| C．Food and drink. | D．Popular style of clothing. |
| A．People’s interests change greatly with age. | B．People’s interests are different from each other. |
| C．It is normal for people to change their interests. | D．It is not good for people to change their interests. |
【推荐3】A new study suggests some of America’s favorite Independence Day fireworks can give out lead and copper (铜), which are used to give fireworks their vivid colors, and also damage human cells and animal lungs.
Led by researchers at NYU, the study showed poisonous levels of lead in the fireworks. Experiments showed that lung exposure to particle emissions (颗粒排放物) from five types of fireworks significantly increased oxidation (氧化), a chemical process in the body that can damage or even kill cells.
The researchers say the new study is believed to be the first to examine the effects of firework exposure in human cells and living animals, and to test for particles of common firework metals thrown into the atmosphere.
“While many are careful to protect themselves from injury from explosions, our results suggest that inhaling firework smoke may cause, longer-term physical damage, a risk that has been largely ignored,” says study senior author Terry Gordon, a professor in the Department of Environmental Medicine.
Gordon and his team also analyzed 14 air quality samples taken at dozens of sites across the US throughout each year. They found that levels of poisonous metals were higher in samples taken on Independence Day and New Year’s Eve celebrations than at any other time of the year. Along with lead, copper and other poisonous metals are commonly found in fireworks. “Our research shows that although we are only exposed to these poisonous substances for a short time each year, they are much more poisonous than the pollutants we breathe every day,” says Gordon.
Gordon cautions (警告) that the current investigation is the first step, only addressing the potential effects of one-time exposure to the firework metals. He says repeated exposure is likely a larger concern. Nevertheless, he is planning to share his findings with local health officials, firework producers, the Environmental Protection Agent, and other regulatory agents to alert them to the potential for harm.
1. Why do some fireworks harm our health?| A．They are oxidized in the air. |
| B．They can give out harmful metals. |
| C．They are exposed to particle emissions. |
| D．They can melt chemical substances in the body. |
| A．Fireworks are the main cause of air pollution. |
| B．Air quality on New Year’s Eve is above normal. |
| C．People breathe in poisonous air for a short time daily. |
| D．Air pollution on Independence Day is worse than usual. |
| A．Remind them not to set off fireworks. |
| B．Caution them against producing metals. |
| C．Alert them to the harm of the experiment. |
| D．Warn them of the possible dangers of fireworks. |
【推荐1】Mangroves typically grow in saltwater along coasts. But some mangroves live in freshwater along the San Pedro Mártir River of Mexico's Yucatán Peninsula. That's nearly 200 kilometers from the sea. Scientists wanted to know how these mangroves got trapped so far inland.
Carlos Burelo was among them. He became curious about these mangroves on a childhood fishing trip. there with his dad 35 years ago. Burelo saw that the roots of the mangroves grew above ground. This was different from the other trees, and it interested him so much. Today, Burelo works at Universidad Juárez Autónoma de Tabasco, Mexico. This biologist is part of a team that went on to discover where those mangroves came from.
Burelo's team first collected leaves from these mangroves. The scientists then compared their DNA to those of leaves from coastal mangroves. The coastal trees were growing along the Caribbean Sea and Gulf of Mexico. The DNA helped find the origins of the mangroves on the San Pedro Marir River. They had started along the Gulf of Mexico, some 170 kilometers away from the river. The river mangroves' DNA and their ages also contained clues about when they separated from their coastal relatives.
The team shared its findings in the Proceedings of the National Academy of Sciences on October 12-More than 100,000 years ago, the world was warmer and Sea levels higher. In fact, sea levels reached about 9 meters above today's levels. As a result, land on what is now the Yucatán Peninsula flooded. That allowed coastal mangroves to move inland. When the world cooled again, the mangroves were stuck for from the coast.
“The remarkable resilience of these trees is striking,” says Burelo.“Although they normally live in seawater, they've survived all this time inland. That is incredible.”
This discovery highlights how changes to the past climate have affected the world's coastlines. It also offers a chance to better understand how future sea level rise may affect these ecosystems .
1. What attracted Burelo's attention on the childhood fishing trip?| A．A typical kind of tree. | B．A trap on the coast. |
| C．A fishing net in the river. | D．A team of biologists . |
| A．To predict possible climate changes. | B．To find the substances they are rich in. |
| C．To separate them from their coastal relatives. | D．To get scientific evidence for the tree's origin. |
| A．Where the team carried out their research. |
| B．What once destroyed the Yucatán Peninsula. |
| C．When the sea level became higher than today's. |
| D．How the sea-loving tree ended up far from the coast. |
| A．Growing period. | B．Economic value. |
| C．Adaptive ability. | D．Ecological function. |
Climate change has caused a rise in sea levels. This has increased an amount of salt in fresh water used on farms near the sea. As a result farmers are unable to use fields close to the sea. Scientists call this process “salinization(盐碱化)”, which is reducing the world’s farm lands by 1 to 2 percent every year.
But a farmer in Holland, Marc Van Rijsselberghe started with an experiment, using a mixture of sea and fresh water to grow healthy and tasty vegetables. He put several kinds of plants in the fields. Mr. Van Rijsselberghe worked on the project with scientists from the Free University of Amsterdam. He divided a farm into eight areas. Every area was watered by different water. “We put in a lot of plants in the fields and then we put them in fresh water and in sea water with all the varieties(变化) between them, and then we saw which variety was surviving and which variety was dying.” A computer program created water with eight levels of salinity(盐度). Computerized measuring devices(测量仪器)controlled the water levels and the levels of salinity.
Mr. Van Rijsselberghe said he was able to harvest vegetables from most of the eight test areas. He said the vegetables were smaller than those grown in fresh water. But he said they had more sugar and salt, so they tasted better.
The farmer grew carrots, potatoes, cabbage and onions. He found that potatoes grew better than the other vegetables in the combination of sea and fresh water. Mr. Van Rijsselberghe said four kinds of these potatoes were recently sent to Pakistan, where thousands of hectares(公顷)of land have been damaged by salinization. Farmers in Pakistan will test the Dutch potatoes to see if they can be grown in those fields.
1. What does the passage mainly talk about?| A．Farms near the sea are becoming less and less in Holland. |
| B．The damage salinization brings to the farms in Holland. |
| C．Farmers improve the skills to make full use of fresh water. |
| D．A Dutch farmer uses a mixture of sea and fresh water to grow vegetables. |
| A．The plant. |
| B．Fresh water. |
| C．Sea water. |
| D．Fresh and sea water. |
| A．salinization brings great benefits to farmers in Holland |
| B．the farmer did the experiment using high technology |
| C．vegetables grew better in sea water than in fresh water in the experiment |
| D．the farmer achieved success without anyone else helping him in the experiment |
| A．had less sugar than those grown in fresh water |
| B．were much bigger than those grown in fresh water |
| C．had a better taste than those grown in fresh water |
| D．had more beautiful colors than those grown in fresh water |
【推荐3】Much of gardening is learned by trial and error — for many, mostly error. But the good news is that we can learn from others’ mistakes as well as our own.
Failing to test the soil
Proper soil pH value is vital for successful gardening. That’s because nutrition is available to plants only at proper pH levels, which vary for each type of plant. For example, blueberry plants will likely turn yellow and produce less if the pH level is higher than 5.5.
Watering incorrectly
Most garden plants require 1 to 1.5 inches of water per week. But leaving the work to a sprinkler (喷头) puts your plants at risk.
A plant labeled as needing “full sun” will likely disappoint you if it is planted in the shade. And no matter how much you hope otherwise, “water tolerant” will never mean “likes wet soil”. Selecting plants suited to your growing conditions will result in a better-looking and healthier garden that requires less care.
Protecting the roots improperly
Proper covering keeps water and helps keep soil temperatures even. So it’s an important part of gardening. Improper covering, however, can kill your plants. Apply 2 to 3 inches of covering around plants. Never pile up against them.
| A．Applying proper nutrition to the soil |
| B．Planting wrong plants at wrong places |
| C．Here are some well-tested tips on good gardening |
| D．Instead, snake a watering tube over the soil surface |
| E．Otherwise, it will lock in too much water and heat which might kill them |
| F．Fortunately, test tools are relatively cheap and available at gardening stores |
| G．Here are some of the common gardening mistakes -and how to avoid them |
