Plants may not have eyes and ears,but they can recognize their siblings (兄弟姐妹),and researchers at the University of Delaware have discovered how.The ID system lies in the roots and the chemical signals they secrete (分泌).
Canadian researchers published that sea rocket,a common seashore plant,can recognize its siblings.Susan Dudley observed that when siblings are grown next to each other in the soil,they “play nice” and don’t send out more roots to compete.However,the moment one of the plants is thrown in with strangers,it begins competing with them by rapidly growing more roots to take up the water and mineral nutrients in the soil.
After reading Dudley’s study,Bais decided to find the method behind the sibling recognition.Working in his laboratory,Bais and his doctoral student Meredith Biedrzycki set up a study with wild populations of Arabidopsis thaliana.In a series of experiments,young seedlings were exposed to liquid media containing the root secretions from siblings,from strangers,or only their own secretions.The length of the longest lateral (侧面的) root was measured.The exposure of plants to the root secretions of strangers induced (引诱) greater lateral root formation than exposure of plants to sibling secretions.Strangers planted next to each other are often shorter,because so much of their energy is directed at root growth.Because siblings aren’t competing against each other,their roots are often much shallower (浅的).
Biedrzycki did the painstaking laboratory research,observing more than 3,000 plants involved in the study every day for seven continuous days and documenting the root patterns.“Arabidopsis roots are nearly translucent (半透明的) when they are young and were also twisted when I removed them from plates,”Biedrzycki notes.“This manuscript (手稿) is very important for my research since the focus of my thesis project is understanding the biochemical ways behind root secretions.”
The research also may have implications for the home gardener.“Often we’ll put plants in the ground next to each other and when they don’t do well,we blame the local garden center where we bought them or we attribute their failure to a germ,”Bais says.“But maybe there’s more to it than that.”
1.Which of the following would be the best title for this passage?
A.A Great Biology Researcher
B.Plants Recognize Their Siblings
C.Plants’ Roots and Secretions
D.A Research on Plants
2. What encouraged Bais to study the sibling recognition?
A.Sea rocket.
B.Plants’ sensing system.
C.Biedrzycki’s thesis project.
D.Dudley’s study.
3. What does the underlined word “painstaking” in Paragraph 4 probably mean?
A.Important. B.Adventurous.
C.Careful. D.Hardworking.
4.What can we infer from the last paragraph?
A.The local garden center should be blamed when plants can’t grow well.
B.The local garden center often sells low quality seeds to customers.
C.Plants in the home garden can’t grow well because of the germ and seeds.
D.Competing against strangers,plants in the home garden can’t grow well.
高三英语阅读理解中等难度题
Plants may not have eyes and ears,but they can recognize their siblings (兄弟姐妹),and researchers at the University of Delaware have discovered how.The ID system lies in the roots and the chemical signals they secrete (分泌).
Canadian researchers published that sea rocket,a common seashore plant,can recognize its siblings.Susan Dudley observed that when siblings are grown next to each other in the soil,they “play nice” and don’t send out more roots to compete.However,the moment one of the plants is thrown in with strangers,it begins competing with them by rapidly growing more roots to take up the water and mineral nutrients in the soil.
After reading Dudley’s study,Bais decided to find the method behind the sibling recognition.Working in his laboratory,Bais and his doctoral student Meredith Biedrzycki set up a study with wild populations of Arabidopsis thaliana.In a series of experiments,young seedlings were exposed to liquid media containing the root secretions from siblings,from strangers,or only their own secretions.The length of the longest lateral (侧面的) root was measured.The exposure of plants to the root secretions of strangers induced (引诱) greater lateral root formation than exposure of plants to sibling secretions.Strangers planted next to each other are often shorter,because so much of their energy is directed at root growth.Because siblings aren’t competing against each other,their roots are often much shallower (浅的).
Biedrzycki did the painstaking laboratory research,observing more than 3,000 plants involved in the study every day for seven continuous days and documenting the root patterns.“Arabidopsis roots are nearly translucent (半透明的) when they are young and were also twisted when I removed them from plates,”Biedrzycki notes.“This manuscript (手稿) is very important for my research since the focus of my thesis project is understanding the biochemical ways behind root secretions.”
The research also may have implications for the home gardener.“Often we’ll put plants in the ground next to each other and when they don’t do well,we blame the local garden center where we bought them or we attribute their failure to a germ,”Bais says.“But maybe there’s more to it than that.”
1.Which of the following would be the best title for this passage?
A.A Great Biology Researcher
B.Plants Recognize Their Siblings
C.Plants’ Roots and Secretions
D.A Research on Plants
2. What encouraged Bais to study the sibling recognition?
A.Sea rocket.
B.Plants’ sensing system.
C.Biedrzycki’s thesis project.
D.Dudley’s study.
3. What does the underlined word “painstaking” in Paragraph 4 probably mean?
A.Important. B.Adventurous.
C.Careful. D.Hardworking.
4.What can we infer from the last paragraph?
A.The local garden center should be blamed when plants can’t grow well.
B.The local garden center often sells low quality seeds to customers.
C.Plants in the home garden can’t grow well because of the germ and seeds.
D.Competing against strangers,plants in the home garden can’t grow well.
高三英语阅读理解中等难度题查看答案及解析
Because plants cannot move or talk, most people believe that they have no feelings and that they cannot receive signals from outside. However, this may not be completely true.
People who studied plants have found out that plants carry a small electrical charge (电荷). It is possible to measure this charge with a small piece of equipment called “galvanometer”. The galvanometer is placed on a leaf off the plant, and it records any changes in the electrical field of the leaf. Humans have a similar field which can change when we are shocked or frightened.
A man called Backster used a galvanometer for his studies of plants and was very surprised at his results. He found that if he had two or more plants in a room and he began to destroy one of them - perhaps by pulling off its leaves or by pulling it out of its pot - then the galvanometer on the leaves of the other plants showed a change in the electrical field. It seemed as if the plants were signalling a feeling of shock. This happened not only when Backster started to destroy plants, but also when he destroyed other living things such as insects (昆虫).
Backster said that the plants also knew if someone had destroyed a living thing some distance away, because they signalled when a man who had just cut down a tree entered the room.
Another scientist, named Sauvin, achieved similar results to Backster’s. He kept galvanometers fixed to his plants all the time and checked regularly to see what the plants were doing. If he was out of the office, he telephoned to find out about the signals the plants were sending. In this way, he found that the plants were sending out signals at the exact times when he felt strong pleasure or pain. In fact, Sauvin could cause a change in the electrical field of his plants over a distance of a few miles simply by thinking about them.
1.Backster was surprised at the results of his studies because _____.
A.he destroyed an insect |
B.he destroyed a plant by pulling off its leaves |
C.he found that plants could express feelings of shock |
D.he found that plants could move and speak after all |
2.The plants sent out signals _____.
A.only when Backster Started to destroy plants |
B.when Backster destroyed plants or other living things |
C.only when he destroyed things such as insects |
D.only when Backster placed the galvanometer on the leaves of the plants |
3.The scientist called Sauvin _____.
A.did not agree with Backster’s ideas |
B.did not get the same sort of results as Backster did |
C.got different results from Backster’s |
D.found out some of the same things that Backster did |
4.Which of the following is true according to the passage?
A.The electrical charge plants carry may shock or frighten us. |
B.A tree will signal when it has been cut down. |
C.Sauvin could make his plants send out signals some distance away. |
D.Plants have feelings because they can receive signals without moving. |
高三英语阅读理解中等难度题查看答案及解析
You may not have played very well today,but at least you’ve got through to the next round and _______.
A.tomorrow never comes B.tomorrow is another day
C.never put off till tomorrow D.there is no tomorrow
高三英语单项填空中等难度题查看答案及解析
Plants are living things. So can they feel pain? Plants don't feel pain the same way animals and people do, says Anke Steppuhn. She is a scientist at the Free University of Berlin in Germany. “What we define as pain usually has to do with a nervous system,” Steppuhn explains. When you put your hand too close to a hot stove, nerve cells send a signal to your brain. Your brain decodes(解码) that signal as pain. This causes you to pull your hand away before any serious damage is done.
Plants don't have nerves or brains, so they can't feel pain like we do. “But plants do recognize when something is hurting them,” Steppuhn says. Because they are rooted to the ground, they can't escape a dangerous situation. So they need other ways of fighting back.
The biggest threat to a plant's life is getting eaten. Some plants grow sharp little hairs. Other plants produce bad-tasting or even harmful chemicals. These force an attacker to abandon its meal. A plant called bittersweet nightshade does something even smarter, Steppuhn found. When a slug(蛞蝓) chews holes in a nightshade' s leaf, liquid begins dripping(滴) around the wound. It is almost as if the plant were bleeding. The liquid is sugary nectar(花蜜), and it happens to be a favorite food of ants. In their effort to collect the nectar, the ants swarm(蜂拥而至) all over the injured plant. They will attack anything that stands in their way. That includes the slug that damaged the plant in the first place. It's a very clever trick. Whenever a slug attacks a plant, the plant calls an army of ants to kill the slug.
Nectar isn't the only way plants attract bodyguards. They also release certain chemicals into the air when they are being eaten. People usually can't detect these smells. But wasps(黄蜂) can. When a wasp detects this cry for help, it races to the scene of the crime. If it finds the right kind of insect chewing down on the plant, the wasp will interrupt the attacker's meal. It will do this by laying eggs inside the insect’s body!
1.Why do plants feel pain differently from us?
A. They don’t know whether they're hurt.
B. They face different kinds of danger.
C. They don’t have nervous systems.
D. They have slow response to pain.
2.What does the underlined word “They” in Paragraph 3 refer to?
A. Ants. B. Slugs. C. Plants. D. Wasps.
3.Why do some plants need wasps?
A. To help them call bodyguards.
B. To keep them safe from attackers.
C. To let wasps lay eggs on their leaves.
D. To let their smells spread into the air.
4.What is the text mainly about?
A. How plants feel pain.
B. How plants attract insects.
C. How plants defend themselves.
D. How plants attack small animals.
高三英语阅读理解中等难度题查看答案及解析
Rabbits are easy to raise. The long-eared animals are clean and quiet. They do not need a lot of room. And you do not have to spend a lot of money to feed them. ________1.________
One male and two females will produce in a year as many as fifty more rabbits. That is enough to provide a good supply of meat for a family.________2.________
Rabbit houses are easy to make with wood and wire fencing material. They do not have to be very big. But each rabbit must have its own little room in the house. This is very important. Each room should be about 75 centimeters wide, 60 centimeters high and one meter deep. Fencing is used for the sides and floor of the rabbit house. The holes in the wire fencing should be about one centimeter square. ________3.________ This keeps the rabbit house clean and dry. Rabbits need a lot of fresh air and sunlight. Cover the sides of the rabbit house only to protect it from rain.
________4.________ Feeding containers hung on the outside of the house let the rabbits eat whenever they want. They simply pull the grass and leaves through the holes in the wire fence.
Each room should have fresh water. The water containers should be heavy so the rabbits cannot turn them over. ________5.________
One month after mating, female rabbits give birth to about eight babies. In two months, a baby rabbit should weigh about two kilograms. This is big enough to make a meal for a small family.
A.Rabbits eat mostly grass and leaves.
B.Rabbits are also valuable for their fur.
C.Or you can tie the containers to the wire.
D.Rabbit meat is high in protein and low in fat.
E. Many people enjoy keeping rabbits as friendly pets.
F. Wastes from the animals will drop through the holes.
G. With rabbits, you get a big return from a small investment.
高三英语信息匹配中等难度题查看答案及解析
33.— We should recycle everything we can.
— Absolutely.These may seem little things,but they’re not__________it comes to saving the
environment.
A.since | B.when | C.while | D.As |
高三英语单项填空简单题查看答案及解析
I don’t remember her name and would not recognize her if I were to pass her on the street. But I do__36__the kindness given by a stranger and the difference it has made in my life.
One Sunday, I was told to dress in my best clothes for I was going to __37__ . She smiled brightly as I got into her car, the car of a __38__I did not even know her name, but here I was , along with four others I __39__from our low-income neighborhood, on our way to church.
As we __40__ into the parking lot, I remember how beautiful the old stone building was with its tall steeple(尖塔)and stained glass windows. The__41__seemed long, and not accustomed to the rituals(仪式)of the Catholic Church, I felt out of place. Once the service had ended, I __42__ to be taken home, but __43__ we headed in the opposite direction. We were taken to a small__44__with the furnishings that portrayed a simple lifestyle. Two tables were set up with large boxes__45__ puzzles. As she made us hot chocolate, we were__46__ to begin working the puzzles. It was a quiet and happy time.
I came to __47__ Sundays,to hot chocolate, to puzzles that__48__ where we had left off the week before, and to the love I felt whenever she __49___at me .
Once our 1,000-piece puzzles had been completed, she no longer came to__50__us up on Sundays .I was told she was__51__ and no longer able to travel. However, I _52__ if perhaps it was time for her to “rescue” the next group of children. To give them hope that kindness still__53__ and can be found within those we call strangers.
I am forty-four years old now and often show__54__to strangers when given the chance. I know she may not move amongst us now, but I hope she smiles when she sees that her efforts to reach out to those less fortunate__55__.
1. A.forget B.understand C.remember D.see
2. A.school B.college C.hospital D.church
3. A.friend B.stranger C.teacher D.leader
4.A recognized B. described C. realized D. offered
5. A.pulled B.pushed C.broke D.stopped
6. A.service B.holiday C.cure D.ceremony
7. A.imagined B.recommended C.expected D.expressed
8. A.besides B.except C.instead D.still
9. A.park B.apartment C.field D.path
10. A.consisting B.concluding C.including D.containing
11. A.instructed B.explored C.convinced D.determined
12. A.pay attention to B.devote to C.look forward to D.lead to
13. A.covered B.replaced C.changed D.remained
14. A.stared B.smiled C.threw D.glared
15. A.make B.pick C.take D.bring
16. A.lost B.gone C.ill D.old
17. A.wondered B.wandered C.hoped D.insisted
18. A.gathers B.exists C.drops D.moves
19. A.respect B.guidance C.signs D.kindness
20.A appear B. fade C. continue D. create
高三英语完型填空中等难度题查看答案及解析
They may be small and not able to speak, but babies are proving their amazing cleverness. Scientists began finding infants’ skills are more than they are supposed to be.
_________
Speaking of music, babies can’t seem to resist it. Not only are their ears turned to the beats, babies can actually dance to the music.
To test babies’ dancing ability, the researchers played recordings of classical music, rhythmic beats and speech to infants, and recorded the results. They also invited professional dancers to analyze how well the babies matched their movements to the music. The babies moved their arms, hands, legs feet and heads in response to the music, much more than to the speech. The finding suggests this dancing ability is innate(与生俱来的) in humans, though the researchers aren’t sure why it becomes weaker later in their life.
Learning Quickly while Sleeping
Babies can learn even while asleep, according to a 2011 study. In experiments with 26 sleeping infants, each just 1 to 2 days old, scientists played a musical tone followed by a puff of air to their eyes 200 times over the course of a half-hour. 124 electrodes(电极) stuck on the head and face of each baby recorded brain activity during the experiments. The babies rapidly learned to foretell a puff of air upon hearing the tone, showing a four-time increase on average in the chances of tightening their eyelids in response to the sound by the end of the experiments.
As newborns spend most of their time asleep, this newfound ability might be crucial to rapidly adapting to the world around them and help to ensure their survival, researchers said.
Judging Characters Well
Judging another person helpful or harmful is crucial when choosing friends. And that ability starts early. Kiley Hamlin of Yale University showed both 6-and 10-month-olds a puppet(木偶) show, in which one character helped another climb a hill. In another scene a third character pushed the climber down. The little ones then got to choose which character they preferred. For both age groups, most babies chose the helper character. This character-judging ability could be baby’s first step in the formation of morals, Hamlin thought.
1.Which of the following subtitles can fill in the underlined blank?
A.Dancing to Music |
B.Babies’ Amazing Abilities |
C.Learning to Dance Quickly |
D.Born to Dance |
2.The underlined word “it” in the third paragraph refers to______.
A.the finding |
B.the dancing ability |
C.the response |
D.the baby |
3.The experiment with 26 sleeping infants prove that_______.
A.babies can learn even while asleep |
B.babies can respond to the world around them |
C.babies can tighten their eyelids in response to the sound |
D.babies can communicate with others while asleep |
4.In the last experiment, most babies chose the helper character, showing that________.
A.babies can judge a person helpful or harmful |
B.babies love to see a puppet show |
C.babies were born to help others |
D.babes have learned to help others |
高三英语阅读理解困难题查看答案及解析
Shorts may feel nice and casual on your legs on a warm summer’s day, but they’re not so gentle on your wallet. 1. Usually the fact that one obviously uses less cloth than the other makes it hard to be accepted So what gives?
It turns out clothing sellers aren’t trying to cheat you by charging you too much money. They’re just pricing shorts according to what it costs to produce them. 2. Extra material does go into a full pair of pants but not as much as you may think. As experts explain, shorts that don’t fall past your knees may contain just a fifth less cloth than ankle-length trousers. 3.
Those same details that end up accounting for most of the material—pockets, belt loops, waist bands—also require the most human labor to make.4.The physical cotton in blue jeans accounts for just a small part of its price Jag. Most of that money goes to pay the people stitching (缝合) it together, and they put in roughly the same amount of time whether they’re working on a pair of pants or some shorts.
5. For another example, short-sleeved shirts cost roughly the same as long-sleeved shirts. There are also numerous invisible factors that make some shorts more expensive than nearly identical pairs, like where they were made9marketing costs, and the brand on the label. If you don’t want to spend $40 on something that covers just a small piece of leg, stay at home with your wallet!
A. More or less, shorts almost cost what pants do.
B. This is where the true cost of a garment is determined.
C. This price trend becomes popular across the fashion field.
D. This is because most of the cloth is sewn into the top half.
E. In general, a pair of shorts isn’t any cheaper than a pair of pants.
F. To tell you the truth, it is a real bargain to pay for a pair of shorts.
高三英语七选五困难题查看答案及解析
They may have text,email,Facebook and Twitter,but young people are still lonelier than any other age group.The Loneliness in New Zealand Report,published by Statistics New Zealand,shows under 30s are more likely to feel lonely than older people because loneliness decreases with age.Loneliness and poor mental health were strongly related across all ages.Young people were not as likely to feel lonely because of financial hardship,but among older people,lack of money was a significant influence on loneliness.Women were more likely to feel lonely than men.
Philip Walker,spokesman for the General Social Survey,said because it was relatively new it was hard to know whether loneliness among young people was a new trend.But overseas research has found that levels of loneliness in youth today are growing.
Mr.Walker said the finding needed more exploration,including looking at the role of technology and social media."It could be that people's expectations of connection have gone up,so we expect increased levels of connection,"he said."While technology like cell phones could help young people stay connected,on the other hand for those who do get bullied(欺辱),especially bullied online,it's quite isolating.A lot of the time potentially it is a big contributor to loneliness."
Figures from online dating website FindSomeone also confirmed more young people were looking for love.Manager Rick Davies,said younger dating hopefuls were the fastest growing group on the site.
Mr.Davies noted that since the report data was collected in 2010there had been huge growth in smart phones,which meant people were online even more.He believed online tools,such as Skype,could help people stay connected."People can keep in touch with a wide range of friends from all over the world much more easily now.It's like you're sitting in your living room having a chat with them."
Bemardine Reid,operations committee chairwoman for Samaritans,which operates a free helpline,said many of their calls came from people who were lonely."It might be that they've got some problem,just like all the things people would normally talk to a friend about,but people who are alone lack those normal contacts."
The Statistics New Zealand report also showed people who didn't have face﹣to﹣face contact with family and friends were more likely to feel lonely,as were those who lived alone.
1.Which of the following may Mr.Walker agree with?
A. High technology may become a reason for loneliness.
B. People shouldn't use the Internet to get to know strangers.
C. It's hard for people to get enough connection online as expected.
D. Social media should play an important role in helping lonely people.
2.It can be inferred from the passage that .
A. FindSomeone is a website where you can find old friends
B. without technology,young people would not feel lonely
C. high technology results in the older being lonely
D. those cheated or hurt online tend to feel lonely
3.From the last two paragraphs,we can conclude that .
A. Internet can keep people free from loneliness
B. people chatting a lot online tend to be optimistic
C. people living alone tend to have more connection online
D. people communicating less in the real world risk loneliness
4.What is the best title of the passage?
A. Loneliness Around You
B. Young People Online
C. Young but Lonely
D. E﹣times and Young People.
高三英语阅读理解中等难度题查看答案及解析