New research suggests that dogs might be able to help save diseased citrus trees.
A group of scientists trained dogs to use their sense of smell to detect a crop disease called citrus-greening. The disease has affected orange, lemon and grapefruit trees in the American states of Florida, California and Texas.
The dogs can detect the disease weeks to years before it appears on tree leaves and roots, the researchers report. A study on their findings was published recently in the Proceedings of the National Academy of Sciences. The report says using dogs is also faster, less costly and more exact than having people collect hundreds of leaves for lab analysis.
Timothy Gottwald is a researcher with the U. S. Department of Agriculture and a co-writer of the study. He told The Associated Press,” This technology is thousands of years old-the dog's nose. We've just trained dogs to hunt new prey. ”
Citrus-greening is caused by a bacteria (细菌) that is spread by a tiny insect that feeds on the leaves and stems of citrus trees. Once a tree is infected(感染), there is no cure. The disease has also hurt citrus crops in Central and South America and Asia. In one experiment involving grapefruit trees in Texas, trained dogs were correct 95 percent of the time in telling the difference between newly infected trees and healthy ones. ”The earlier you detect a disease, the better chance you have at stopping an epidemic(流行病)by removing infected trees, ”Gottwald said.
Matteo Garbelotto studies plants at the University of California, Berkeley. He says the new research shows that dogs can detect an infection well before current methods. Garbelotto has been involved in similar research but had no part in the new study.
Laura Sims is a plant scientist with Louisiana Tech University. She praised the steps taken to find out if the dogs were detecting the bacteria itself or a plant's reaction to an infection. To do that, the researchers infected different kinds of unrelated plants with the bacteria in a laboratory. The dogs were still able to pick out the infected plants.
Gottwald said, “You've seen dogs working in airports, detecting drugs and explosives. Maybe soon you will see them working on more farms. ”
1.According to the research, trained dogs can
A.help infected trees recover from diseases
B.recognize a crop disease in its early stage
C.cause fruit trees to grow faster than usual
D.reduce the cost of planting some fruit trees
2.What does the underlined part “new prey” in Paragraph 4 refer to?
A.Infected plants. B.Fruit trees. C.Tiny insects. D.Favourite foods.
3.Why did the researchers do experiments on unrelated plants?
A.To further prove the findings. B.To explore the plant diseases.
C.To present different opinions. D.To discover a plant's reactions.
4.How does Gottwald feel about the future use of this new method?
A.Doubtful. B.Confident. C.Uninterested. D.Curious.
高一英语阅读选择中等难度题
New research suggests that dogs might be able to help save diseased citrus trees.
A group of scientists trained dogs to use their sense of smell to detect a crop disease called citrus-greening. The disease has affected orange, lemon and grapefruit trees in the American states of Florida, California and Texas.
The dogs can detect the disease weeks to years before it appears on tree leaves and roots, the researchers report. A study on their findings was published recently in the Proceedings of the National Academy of Sciences. The report says using dogs is also faster, less costly and more exact than having people collect hundreds of leaves for lab analysis.
Timothy Gottwald is a researcher with the U. S. Department of Agriculture and a co-writer of the study. He told The Associated Press,” This technology is thousands of years old-the dog's nose. We've just trained dogs to hunt new prey. ”
Citrus-greening is caused by a bacteria (细菌) that is spread by a tiny insect that feeds on the leaves and stems of citrus trees. Once a tree is infected(感染), there is no cure. The disease has also hurt citrus crops in Central and South America and Asia. In one experiment involving grapefruit trees in Texas, trained dogs were correct 95 percent of the time in telling the difference between newly infected trees and healthy ones. ”The earlier you detect a disease, the better chance you have at stopping an epidemic(流行病)by removing infected trees, ”Gottwald said.
Matteo Garbelotto studies plants at the University of California, Berkeley. He says the new research shows that dogs can detect an infection well before current methods. Garbelotto has been involved in similar research but had no part in the new study.
Laura Sims is a plant scientist with Louisiana Tech University. She praised the steps taken to find out if the dogs were detecting the bacteria itself or a plant's reaction to an infection. To do that, the researchers infected different kinds of unrelated plants with the bacteria in a laboratory. The dogs were still able to pick out the infected plants.
Gottwald said, “You've seen dogs working in airports, detecting drugs and explosives. Maybe soon you will see them working on more farms. ”
1.According to the research, trained dogs can
A.help infected trees recover from diseases
B.recognize a crop disease in its early stage
C.cause fruit trees to grow faster than usual
D.reduce the cost of planting some fruit trees
2.What does the underlined part “new prey” in Paragraph 4 refer to?
A.Infected plants. B.Fruit trees. C.Tiny insects. D.Favourite foods.
3.Why did the researchers do experiments on unrelated plants?
A.To further prove the findings. B.To explore the plant diseases.
C.To present different opinions. D.To discover a plant's reactions.
4.How does Gottwald feel about the future use of this new method?
A.Doubtful. B.Confident. C.Uninterested. D.Curious.
高一英语阅读选择中等难度题查看答案及解析
Many of us spend part of each day surrounded by strangers, whether on our daily commute (上下班往返), or sitting in park or cafe. But most of them remain just that-strangers. However, new evidence has shown that plucking up (鼓起) the courage to strike up conversation might be good for our health.
Nicholas Epley from the University of Chicago and Juliana Schroeder from the University of California are behavioural scientists. They wanted to know whether solitude is a more positive experience than interacting with strangers, or if people misunderstand the consequences of distant social connections. They found that many people feel uncomfortable and frightened talking to others and their research suggested that when we make an initial conversation “we consistently underestimate (低估) how much a new person likes us.” It seems we think that all the things could go wrong and why someone wouldn’t want to talk with us.
Their research involved an experiment with a group of Chicago commuters and found that “every participant in our experiment who actually tried to talk to a stranger found the person sitting next to them was happy to chat.” From this and other research, the conclusion is that connecting with strangers is surprisingly pleasant and it has a positive impact on our wellbeing. It’s true that talking can make you feel happier and happiness can lead to better mental health.
However, if you’re’ an introvert (性格内向者), the thought of speaking to someone new might make you anxious. But the American research found “both extroverts (性格外向者) and introverts are happier when they are asked to behave in an extroverted manner.” So maybe, if you’re a loner, it’s time to come out of your shell and make some small talk with a stranger-it could be the beginning of a new friendship.
1.What does the underlined word“solitude”in paragraph 2 mean?
A.Being calm. B.Being pleasant. C.Being alone. D.Being healthy.
2.Why might we not want to speak to a stranger?
A.Because we don’t trust a new person.
B.Because we can’t find a common topic.
C.Because we like distant social connections.
D.Because we carry a negative voice in our head.
3.What could help start a new friendship?
A.Making a small talk. B.Sitting next to a stranger.
C.Sharing personal details. D.Behaving in polite manner.
4.Which of the following is the best title for the text?
A.How to be an extrovert. B.Talking to strangers.
C.How to speak to strangers. D.Making new friends.
高一英语阅读选择困难题查看答案及解析
Could your next pet be a goat? New research suggests that these farm animals try to communicate with people in the same way that dogs and horses do. In a series of experiments, researchers found that when the animals had a problem that they couldn’t solve alone,the goats would gaze at a person for help. The research also shows that goats will change their actions according to a person’s behavior.
Goats were the first domesticated(驯化为)livestock species, about 10,000 years ago, according to Alan McElligott. “From our earlier research, we already know that goats are smarter than people think, but these results show how they can communicate and interact with people even though they were not domesticated as pets or working animals,” McElligott said in a statement.
To test the goats’ communication skills, the researchers trained the animals to remove the lid from a box to receive a reward. The reward was then made inaccessible(得不到的,不能接近的), and the goats’ reactions toward the experimenters—who were either facing the goats or had turned away—were recorded. The researchers found that the goats would gaze at the forward-facing person more often, and for longer periods of time. Sometimes, the goats would also approach the forward-facing person before returning to the box.
“Goats gaze at humans in the same way as dogs when asking for a treat that is out of reach,” study researcher Christian Nawroth said in the same statement. “Our results provide strong evidence for communication directed at humans in a species that was domesticated mainly for agricultural product, and goats show similarities with animals bred to become pets or working animals,such as dogs and horses.”
The authors said that they hope the study will help people to better understand domesticated animals like goats, dogs and horses, and how they interact with humans.
1.The underlined word “they” in the first paragraph refers to .
A. the researchers B. the horses
C. the goats D. the dogs
2.What did the goats do after they couldn’t receive the reward?
A. They refused to remove the lid.
B. They stared at the experimenters.
C. They turned away.
D. They returned to the box quickly.
3.What is the aim of the research?
A. To study the habits of animals in order to understand their feelings.
B. To raise more domesticated animals like goats, dogs and horses.
C. To show the similarity between goats and dogs.
D. To make people better understand domesticated animals.
高一英语阅读理解中等难度题查看答案及解析
The possibility that pleasant smells might reduce pain has recently been suggested by new research. In a scientific study, doctors asked 20 men and 20 women to keep their hands in very hot water for as long as possible while breathing in different smells.
As people believe that strong smells can affect the senses, volunteers were asked not to eat or drink for eight hours before the experiment began. During the experiment, volunteers were asked to take in pleasant smells such as vanilla (香草), and unpleasant smells such as durians (榴莲). The volunteers kept their hands in the water until it became too hot for them. When they could not bear the pain any more, they took their hands out of the water.
Scientists are interested in whether the senses or smell is related to pain and whether men and women have the same senses. Now, the study has proved that for women, pleasant smells reduce pain. For men, there is no change.
Dr Finkelstein has been studying smells since 1999. He says that scientists already have data from 40 volunteers. He adds that this year, scientists will test another 60 volunteers and will be in a better position to explain the results.
One explanation is that women’s sense of smell developed long ago, and is linked to recognizing the smell of babies. Scientists used to believe that mothers recognized their children by sight only. Now, they have started to believe that the sense of smell also helps, but why pleasant smells do not reduce pain in men is a question still to be answered by scientists.
1.Before the experiment, volunteers ______.
A.are gathered and take a training
B.cannot eat or drink for several hours
C.must wash their hands carefully
D.will be interviewed by Dr Finkelstein
2.If both men and women are asked to keep their hands in hot water while taking in some pleasant smells, ______.
A.women may stand the pain of the hot water longer
B.men may keep their hands in the hot water longer
C.they will probably take their hands out at the same time
D.we are not quite sure who will take their hands out earlier
3.From the passage we learn that _________.
A.the reason why women are sensitive to smells is clear
B.the experiment for the sense of smell has come to an end
C.unpleasant smells affect men’s senses more than women’s
D.scientists have not totally explained the result of the study
4.Now scientists believe that _______.
A.mothers recognize their children only by sight
B.men’s sense of smell developed a long time ago
C.strong smells have a great influence on people’s senses
D.smells are helpful for mothers to spot their children
5.The writer wrote the passage in order to ________.
A.supply some entertainment to us
B.show women’s sharper senses than men’s
C.inform the readers of some knowledge
D.call for volunteers for the experiment
高一英语阅读理解中等难度题查看答案及解析
A breathtaking trick potentially left over from our ancestors might be found in us-the ability to sense oxygen through our skin.
Amphibians, animals such as frogs that can live both on land and in water, have long been known to be capable of breathing through their skin. In fact, the first known lungless frog that breathes only through its skin was discovered recently in the rivers of Borneo.
Now the same oxygen sensors found in frog skins and in the lungs of mammals have unexpectedly been discovered in the skin of mice. “No one had ever looked,” explained Randall Johnson, a biologist researcher. Mice and frogs are quite distant relatives, so the fact they have these molecules in common in their skin suggests they might well be found in the skin of other mammals, such as humans. “We have no reason to think that they are not in the skin of people too.” Johnson said.
These molecules not only detect oxygen, but help increase levels of vital red blood cells, which carry oxygen around the body. Normal mice breathing in air that is 10 percent oxygen-a dangerously low level similar to conditions at the top of Mount Everest, and about half that of air at sea level. However, mice that had the oxygen sensor HIF-la genetically removed from their skin failed to produce this hormone even after hours of such low oxygen.
These findings, if they hold true in humans, suggest one could raise the level of oxygen circulating inside the body. This could help treat lung diseases and disorders such as anemia without injecting drugs, which make up a multibillion- dollar market, Johnson said.
Athletes also often try to get more oxygen delivered to their muscles in order to improve their performance. They often do this by training at high altitudes or in low-oxygen tents. The new study suggests they might want to expose their skin as well as breathing in low-oxygen air to improve their performance. “It's hard to say what exactly might be done, however-there's a lot we don't know yet,” Johnson explained. The scientists detailed their findings in the April 18 issue of the journal Cell.
1.Which of the following statements is TRUE according to the passage?
A.Johnson believes that Oxygen sensors also exist in human skin.
B.People have to surf the Internet to read detailed findings.
C.It has been proved that these findings help treat lung diseases.
D.It has long been expected oxygen sensors exist in mice's skin.
2.One of the functions of the molecules mentioned above is
A.carrying-oxygen around the body
B.improving athletes'performance
C.detecting oxygen
D.increasing level of oxygen
3.What is Johnson's attitude to the application of the findings to the athletes'training?
A.Negative B.Pessimistic C.Positive D.Hesitating
4.The best title of the passage may be
A.Great Findings Benefits Athletes A Lot
B.Frogs And Mice Are Distant Relatives
C.First Known Animal Breathes Through Skin
D.Humans Might Sense Oxygen Through Skin
高一英语阅读选择中等难度题查看答案及解析
Imagine that you are in a remote village somewhere with no medical clinic. 1.Once the doctors get to you, they examine you and take blood samples, but they won't be able to help you until they take the samples back to the hospital to find out what is wrong.2. Thanks to engineer Andy Ozcan, many people may never be in this situation. He has invented an app that turns your mobile phone into a diagnostic(诊断的)tool.
Ozcan's invention is important because it is very accurate and easy to use. In many remote places, even if doctors have microscopes and other instruments to help them make diagnoses, there may still be other problems. Many doctors, for example, don’t have enough training to correctly interpret what they see.3.With Ozcan's mobile phone app, health workers can take a special photo of a blood sample and send it to a central computer at a hospital. The computer will then automatically interpret the photo and send a diagnosis back in a few minutes.
4.His technology only requires a mobile phone and an Internet connection. As more than four billion people already have cell phones, the cost of establishing the diagnostic system is fairly low.
By inventing a medical tool that uses existing technology---mobile phones---Ozcan has developed a medical tool that is both practical and economical. Therefore, it can be effectively almost anywhere.5.
A.Another reason that Ozcan's invention is important is that it is inexpensive.
B.Even though you may only have a simple infection (感染), you might die because of the delay.
C.People are trying to reduce the cost of this new medical tool.
D.Ozcan's simple, cost-effective tool might just save millions of lives around the world.
E.This tool has become much more popular all around the world.
F.You become very sick and must wait days until a mobile medical unit arrives to help.
G.As a result, they may diagnose illnesses incorrectly.
高一英语七选五困难题查看答案及解析
Compared to other causes of natural disasters, volcanoes offer clues only when they are about to erupt. Now, however, developments in monitoring systems have allowed scientists to develop sensors to detect and forecast eruptions more accurately.
University of Cambridge volcanologist Marie Edmonds says that scientists are now able to use very accurate sensors to monitor the gases volcanoes give out, which can give clues on the location of the magma. The sensors help with prediction because different gases are released at different stages of an eruption. When magma rises, pressure is released along with gases. Carbon dioxide is released early on and then, as the magma goes higher, Sulphur dioxide is released. The ratio of the two gases is used to detect the location of magma relative to the surface, telling researchers the coming of the eruption.
Edmonds is connected to an international group known as the Deep Carbon Observatory that has worked to put new gas sensors on fifteen of the most active and dangerous volcanoes to improve the forecasting of various types of eruptions. The gas sensors continually measure water vapor, sulphur dioxide, and carbon dioxide. They are placed inside large boxes with surface antennae and buried underground. Advances in electronics have increased their accuracy and lowered their cost, allowing more of them to be used worldwide.
Putting these sensors atop active volcanoes is dangerous. Scientists wear reflective suits that protect against heat, plus gas masks for protection from dangerous gases. They sometimes hike long distances in remote areas to reach a site. However, according to Edmonds, the work they do to save people’s lives makes a dangerous job worth it. She enjoys doing something that helps people.
Edmonds’ team has also attached sensors to a certain plane to measure gases released from a Papua New Guinea volcano for a short time, a technique developed to gather “snapshots” of the activity. These snapshots help researchers to better understand activities that lead to eruptions.
1.How do sensors detect and predict volcanic eruptions?
A.By sending warnings to researchers. B.By testing different gases released.
C.By measuring the heat underground. D.By studying the surrounding gases.
2.What do we know about the gas sensors?
A.They should be attached to the magma. B.They are available around the world.
C.They become more accurate and expensive. D.They can check various types of eruptions.
3.Why is it risky to place sensors atop active volcanoes?
A.Active volcanoes may erupt at any time. B.It’s hard to find the top of volcanoes.
C.Scientists are short of enough suits and masks. D.There is heat and dangerous gases
4.What can the snapshots do?
A.Predict volcanic eruptions earlier. B.Attract people’s attention to volcanoes.
C.Collect more information for researchers D.Avoid the danger of the researchers’ work.
高一英语阅读选择中等难度题查看答案及解析
Crossing your legs is an extremely common habit; most people don’t even notice that they’re doing it when they sit down. While you may find it comfortable to sit with one knee crossed over the other, it might be causing health problems that you are not aware of.
A study published in Blood Pressure Monitoring stated that sitting with your legs crossed can increase your blood pressure. The reason is that the blood in your legs has to work against gravity to be pumped back to your heart and that crossing one leg over the other increases resistance, making it even harder for the blood to circulate. This causes your body to increase your blood pressure to push the blood back to the heart. You won’t feel any immediate effects, but repeated, drawn-out increases in blood pressure can cause long term health problems. So, panning to sit for a long period of time? Don’t keep your legs crossed.
Crossing your legs at the knee can also cause pressure on the major nerve in your leg that passes just below your knee and along the outside of your leg, explains Richard Graves, a medical expert. This pressure can cause numbness and temporary paralysis of some of the muscles in your foot and leg, preventing you from being able to raise your ankle. While the feeling of discomfort may only last a minute or two, repeatedly crossing your legs until they feel numb can cause permanent nerve damage.
So next time you sit down, try to get yourself in the habit of sitting with both of your feet on the floor. Not only will it help your posture and stability, but it will also save your health in the long run.
1.What can we learn about crossing one’s legs?
A.It is a very bad social habit. B.It is usually practiced by design.
C.It can make others feel uncomfortable. D.It has a negative effect on people’s heath.
2.We may conclude from the study that sitting with your legs crossed can ________.
A.improve the function of legs B.help your blood resist gravity
C.effect your blood pressure D.cause health problems instantly
3.According to Richard Graves, repeatedly crossing your legs may ________.
A.paralyze all of your muscles B.preventing you from standing up
C.damage your nerve in the leg in the end D.reduce the pressure on the major nerve
4.What is the main purpose of the text?
A.To blame a bad habit. B.To provide suggestions.
C.To introduce research methods. D.To show effects of an experiment.
高一英语阅读选择中等难度题查看答案及解析
Bumblebees(大黄蜂) are clever: when pollen(花粉) is short and plants near the nest are not yet flowering, they have learned to force them to bloom. Research published on Thursday in Science shows that the insects puncture the plants’ leaves, which causes them to flower about 30 days earlier than they otherwise would. How the technique developed and why the plants react by blooming remain unclear.
Consuelo De Moraes, a chemical ecologist at the Swiss Federal Institute of Technology, says she and her teammates were observing one kind of bumblebee in an unrelated experiment when they noticed the insects were damaging plant leaves and wondered why. “At first we thought they might be feeding on the plants,” she says. And because previous research had shown stress could cause plants to flower, they also wondered whether the bees might be creating blooms on purpose.
To find out, the team placed bumblebees together with tomato plants in cages. The bees soon cut several holes in the leaves of each plant. As a test, the researchers tried to copy the bumblebee damage in additional plants with a knife. Both sets of plants with injured leaves bloomed faster, but the ones punctured by the bees flowered weeks earlier, suggesting that chemicals in the insects’ saliva(唾液) may be involved as well.
Next, the researchers moved out of the laboratory to see whether bumblebees would continue to damage nonflowering plants near their nest even if blooming plants were available farther away. They did so. The findings suggest the bees’ behavior is an adaptation that improves food-hunting efficiency(效率).
In the future, scientists could test how the behavior may have developed and how widespread it is among other wild bumblebees, as well as what is happening in plants after a bee bite. Understanding those questions could help us better face the climate change.
1.What does the underlined word “puncture” in Paragraph 1 probably mean?
A.bite B.touch
C.kiss D.eat
2.What inspired Consuelo and her team to do the present research?
A.The stress causing plants to flower. B.The difference in plants’ flowering time.
C.The bumblebees’ feeding on the plants. D.The bumblebees’ damaging plants’ leaves.
3.Why did the researchers copy what the bumblebees did?
A.To prove a knife cut can work as a bee bite.
B.To figure out what helps plants flower faster
C.To find out why bumblebees damage plants.
D.To show bumblebees’ saliva helps plants bloom.
4.What have the researchers made clear?
A.What happens in plants after a bee bite.
B.How bumblebees have learned the technique.
C.Whether bumblebees are clever in finding food.
D.Whether all the bumblebees have learned the skill.
高一英语阅读选择中等难度题查看答案及解析
Dog owners walked about 23minues longer each day than non-dog owners In a new study, dog owners took 2,760 additional seps—compared to people who didn’t have a dog at home. Bu here’s the real good news: That extra exercise was done at a moderate(适度的)pace, which means it could help adults meet their recommended weekly totals for physical activity.
The research, published in BMC Public Health, focused on adults 65 and older, who tend to be less active than younger people. The study included 43 dog owners and 43 non-dog owners, all of whom were monitored continuously for three week-long periods. When they compared the two groups, the researchers found that dog ownership was associated with a large, potentially health-improving effect.
Dog owners walked about 23 minutes longer each day than non-dog owners, 119 minutes versus 96 minutes on average. They also took an additional 2,760 steps, and had eight fewer continuous periods of sitting down. Most of that extra walking was done at moderate pace, defined as 100 or more steps a minute. Dog owners walked at this pace for 32 minutes a day, versus just 11 minutes a day for non-dog owners.
The World Health Organization(WHO)recommends that adults get at least 150 minutes of physical activity a week. This increased walking time alone could just about satisfy that requirement, say the researchers—so it makes total sense that 87 percent of dog owners in the study met these guidelines, versus just 47 percent of non-dog owners.
Co-author Nancy Gee says that pet ownership may help older adults get more activity or maintain their current activity level for a longer period of time. “This could improve their chances of a better quality of life, improved or maintained cognition(认知), and perhaps, even overall longevity(寿命),”she said.
Here at Health, we’ ll add that caring for pets has been shown to have plenty of other physical and mental health benefits, as well. As animal lovers ourselves, we’ re happy to add one more to the list.
1.What can we learn about the research?
A.It was targeted on old people.
B.It was sponsored by the WHO.
C.It had an undesirable effect on dog owners.
D.It took the mental health of dog owners into consideration.
2.What does the author intend to do in Paragraph 3?
A.To present the results of the research.
B.To show the guidelines of the research.
C.To describe the process of doing the research.
D.To explain the reasons for conducting the research.
3.What does Nancy Gee think of owning a dog?
A.It is too expensive.
B.It is time-consuming.
C.It enables older adults to live a healthy life.
D.It helps young adults to keep a healthy routine.
4.What is the best title for the text?
A.Non-pet owners enjoy more pleasure
B.Animal lovers are more generous
C.Young people walk less today
D.Dog owners walk way more
高一英语阅读选择中等难度题查看答案及解析