题目
题型：不详难度：来源：
But things are not as easy for plants. Unlike humans, plants can’t move to escape the cold or generate heat to keep themselves warm. So how do they manage to survive the freezing winter?
It turns out that plants have their own strategies 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 can be damaged when they freeze. “It’s like a plant’s equivalent to frostbite (冻疮),” Zanne told Science Daily. Also, the process of freezing and thawing (解冻) can cause air bubbles 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, according to the study. Some plants, such as oak trees, 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 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. 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.
小题1: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. |
| 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 |
| A．By dropping their leaves before winter. |
| B．By narrowing their water transport cells. |
| C．By widening their water transport cells. |
| D．By leaving only the seeds alive and growing from the seeds in the spring. |
| 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. |
答案
小题1:B
小题2:D
小题3:A
小题4:C
解析
试题分析：在寒冷的冬天，人们有各种各样保暖的方法，但是植物怎么过冬呢？这篇文章讲的是植物在寒冷的天气生存的方法。
小题1:主旨题：从全篇文章和第二段的句子：But things are not as easy for plants. Unlike humans, plants can’t move to escape the cold or generate heat to keep themselves warm. So how do they manage to survive the freezing winter?可知这篇文章讲的是植物在寒冷的天气生存的方法，选B。
小题2:细节题：从第四段的句子;“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,” 可知如果植物在冬天被冻住了，会影响它们的水运输系统在春天就会被堵塞，所以选D。
小题3:细节题：从第五段的句子：Some plants, such as oak trees, avoid freezing damage by dropping their leaves before the winter chill sets in – effectively shutting off the flow of water between roots and leaves 可知橡树是通过在冬天将树叶落下，这样来在冬天幸存的，选A。
小题4:细节题：根据文章倒数第二段的句子：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.可知科学家担心的是植物可能不能进化的那么快来适应人类造成的气候变化。C
核心考点
试题【IT’S never a real problem for us when the weather gets cold. We can put on more 】；主要考察你对题材分类等知识点的理解。[详细]
举一反三
Now it looks like you are one step closer to this wild dream of yours – scientists from Oxford University, UK have just discovered the “switch” that tells the brain to go to sleep, reported Forbes.
To understand the study, you first need to know that there are two mechanisms (机能) that regulate sleep. There’s one that we’re already familiar with – our body clock, which works in a 24-hour cycle based on the light changes throughout the day.
The other one is what scientists call the sleep “homeostat (动态平衡系统)”. This mechanism has nothing to do with daylight. Instead, it keeps track of the brain’s waking hours and urges it to rest if it has been awake for a long time. “It is similar to the thermostat (自动调温器) in your home. A thermostat measures temperature and switches on the heating if it’s too cold,” Professor Gero Miesenböck, who led the study, told The Telegraph.
Our bodies use both of the mechanisms to regulate sleep. “The body clock says it’s the right time, and the sleep thermostat has built up pressure during a long waking day,” explained Miesenböck.
There is no way that scientists can trick the body clock. But with the sleep homeostat, there might be something they can do.
The researchers found that the sleep homeostat works by activating a specific group of nerve cells, or neurons, in the brain. They tested their theory on fruit flies by removing the neurons from the insects’ brains. And as expected, they found that the flies without the homeostat neurons did not keep a regular sleep pattern anymore.
Now that scientists have pinpointed (定位) the exact place in the brain – or, the “switch” – that regulates sleep, they can begin investigating (研究) how to activate these cells at any given time so that people can be sent to sleep instantly.
More importantly, figuring out how sleep mechanisms work may also help us to one day unravel one of the oldest mysteries of all: why do we need to sleep in the first place?
小题1:What is the article mainly about?
| A．A new way to treat sleep disorders. |
| B．The discovery of the sleep “homeostat”. |
| C．Advice on what to do when you fail to fall asleep. |
| D．A comparison of the two mechanisms that regulate sleep. |
| A．Through examples. |
| B．With comparisons. |
| C．Through cause and effect analysis. |
| D．By presenting research findings. |
| A．Generally, the sleep homeostat has less effect on people during the day than at night. |
| B．There is little scientists can do to affect the way the sleep homeostat works. |
| C．What makes us go to sleep at night is probably a combination of the two mechanisms. |
| D．The more homeostat neurons there are in one’s brain, the more easily one can fall asleep. |
| A．put up with | B．figure out | C．keep track of | D．take notice of |
This was the conclusion of a team of scientists from China"s State Forestry Administration and the World Nature Fund.
The South China tiger, also known as the Chinese tiger, is native to southern China. In the 1950"s, there were over 4000 tigers found in mountain forests in the country. But due to the destruction of their natural habitat and uncontrolled hunting, it has been pushed on to the list of the world"s top ten most endangered species.
Sixtysix of the big cats can be found in the cages of a dozen zoos around China. But they are nothing like their wild cousins. They have lost their natural skills such as hunting and killing. If they were set free they could not look after themselves.
“Breeding has damaged the quality of the species”, said Pei Enle, deputy director of the Shanghai Zoo.
To reintroduce the species into the wild, the country started a programme to send five to ten young tigers to South Africa. Four of them have already arrived. Progress has been made as two elder tigers have recovered some of their instincts(本能) and can hunt wild animals by themselves at the African base.
“South Africans are very experienced in reintroducing big animals to the wild. The country has very good natural conditions for the tigers to learn in”, said Lu Jun, office director of the National Wildlife Research and Development Center.“We tried in Fujian Province, but it was not successful as there was not a complete ecochain(生物链) and there was a lack of space.”
The tigers should return to China in 2007 when the reservations in Fujian are ready.
小题1:What is the main reason for the South China tiger becoming one of the world"s top ten most endangered species?
| A．Because it has lost its natural instincts. |
| B．Because there is not a complete ecochain. |
| C．Because there is no space for it. |
| D．Because uncontrolled hunting has destroyed its natural living conditions. |
| A．Its effect still remains to be seen. |
| B．Two tigers can already compete with their wild cousins. |
| C．Some of the tigers are already on the road to recovering their natural skills. |
| D．The tigers should be able to recover their instincts completely by 2007. |
| A．they are no longer feared by other wild animals |
| B．they don"t know how to hunt or kill |
| C．a complete change has resulted in the species because of breeding |
| D．to reintroduce them into the wild has become an urgent task |
| A．To help the tigers recover their ability to live in the wild. |
| B．To provide them with a better environment. |
| C．To get the tigers to go on a tour. |
| D．To find a complete ecochain for them. |
| A．Because the tigers can hunt wild animals by themselves at the African base. |
| B．Because South Africans are skilled at dealing with the tigers. |
| C．Because there is a complete ecochain and enough space there. |
| D．Because the country has good natural conditions for the tigers to learn in. |
Lead researcher Omri Gillath said the judgments were based on the style，cost，color and condition of someone’s shoes．In the study，63 University of Kansas researchers looked at pictures showing 208 different pairs of shoes worn by the study’s participants.Volunteers in the study were photographed in their most commonly worn shoes，and then filled out a personality questionnaire．
Some of the results were expected：People with higher incomes most commonly wore expensive shoes，and flashier shoes were typically worn by outgoing people．However，some of the more specific results are strange enough．For example，“practical and functional’’shoes were generally worn by more“pleasant"people，while ankle boots were more linked with ‘‘aggressive’’personalities．The strangest of all may be that those who wore‘‘uncomfortable looking” shoes tend to have “calm” personalities. And if you have several pairs of new shoes or take extreme care of them，you may suffer from“attachment anxiety"，spending lots of time worrying about what other people think of your appearance．There was even a political calculation in the mix with more liberal(主张变革的)types wearing“shabbier and less expensive” shoes．
The researchers noted that some people will choose shoe styles to mask their actual personalities，but researchers noted that volunteers were also likely to be unaware that their footwear choices were showing the deep side of their personalities．
小题1:What does this text mainly tell us?
| A．People’s personalities call be judged by their shoes． |
| B．Shoes convey false information about the wearer． |
| C．People know little about their personalities． |
| D．Shoes Call hide people’s real personalities． |
| A．look at pictures of different shoes |
| B．provide pictures of their shoes |
| C．hand in their commonly worn shoes |
| D．design a personality questionnaire |
| A．Pleasant people like wearing uncomfortable shoes． |
| B．Wealthy people often wear expensive shoes． |
| C．Flahshier shoes are typically worn by outgoing people． |
| D．Aggressive people are likely to weal"ankle boots． |
| A．become a political leader |
| B．have a calm character |
| C．worry about their appearance |
| D．wear strange shoes |
| A．teach how to choose shoes |
| B．describe different personalities |
| C．inform us of a new study |
| D．introduce a research method |
With so many photos and videos of cats and dogs doing cute things online, it’s easier than ever to answer which of these furry friends you like more. There are many reasons why people prefer one type of pet over the other. So, have you ever wondered what your preference for cats or dogs says about you?
In fact, a 2010 study done by Sam Gosling , a psychologist at the University of Texas, US, and his graduate student Carson Sandy found that dog people are more extroverted（外向的）agreeable and serious than cat people.
“Cats will occasionally engage in social activities, but usually after only a few minutes they will abandon the game. Dogs, on the other hand, will often engage in play, like fetching a thrown lull, for hours at a lime," said Modem Dog magazine.
Just on the basis of dogs" nature being more sociable than cats’, you may expect that the personalities of dog people also reflect higher sociability. And Cosling’s study found that dog people are generally about 15 percent more extroverted and 13 percent more agreeable, both of which are associated with social altitude.
In addition, dog people are 11 percent more conscientious than cat people.
“Conscientiousness" is a tendency In show self-discipline（自律）,to complete tasks and aim for achievement. This quality also shows a preference for planned rather than spontaneous （一时冲动的） behavior.
In comparison, cat people an; about 12 percent more anxious, but they are also 11 percent more “open” than dog people, due to a general appreciation for art, emotion, imagination, curiosity, adventure, unusual ideas and variety of experience. And people high on openness are more likely to hold unconventional beliefs.
Despite vast differences, there an some things that cat people and dog people have in common. “Both types of people consider themselves close to nature, dislike animal-print clothing and generally optimists. ” noted Mother Nature Network.
小题1:What does the article mainly talk about?
| A．Differences between dogs and cats in their personality qualities. |
| B．Factors that influence people’s preference for dogs or cats. |
| C．How raising a pet helps shape your personality. |
| D．What your preference for dogs or cats reveals about you. |
| A．get involved in | B．benefit from |
| C．take little interest in | D．perform well in |
| A．be more imaginative and creative |
| B．live a more organized life |
| C．love to get close to nature more |
| D．be more easygoing and adventurous |
| A．are generally self-disciplined |
| B．are usually positive and care about nature |
| C．are likely to hold unconventional beliefs |
| D．like to wear animal-print clothing; |
Yes, sportsmen tend to be handsome. And they haven’t only attracted the interest of the audience even scientists are now studying their good looks.
In a recent study, Erik Postma, a biologist at the University of Zurich in Switzerland, collected the headshots（头像）of 80 professional athletes from I hr 2012 Tour He France, a bicycle race held in Franco. The race, which covers 3,200 kilometers in 23 days, is often considered to In* one of the hardest endurance（耐力）events, according to The Telegraph.
Postma then asked female participants to score the cyclists’ attractiveness.judging them only based on their facial appearances. So, if a participant recognized any of the cyclists, meaning she knew how good he was at the sport, her score wouldn’t count.
After comparing all the scores with the cyclists’ performances in the 2012 race, Postma was surprised to find that the best riders were rated on average 25 percent more attractive than the worst ones. For example, one of the cyclists, Maxime Monfort , came third in terms of attractiveness and sixth in terms of performance, reported Discovery News.
But where did women get the ability to single out a good rider by simply looking at his face?
According lo Postma, evolution (进化) seems to be the answer. In ancient times, women preferred to marry strong men because they would provide good genes for their children. A man with great endurance was also able to cover long distances to hunt for food, which would allow him to better feed the family. “That’s why endurance performance was a key evolutionary factor.” Postma told Discovery News.
As you can see, it’s not that sportsmen ate more attractive themselves, women were just born to think of them that way.
Perhaps surprisingly, when Postma did the same test with male participants, he found that men actually had a quite similar view on which riders were handsome. Even
though most men aren’t aware of it. they inherited (继承) this ability from their ancient past, when it was necessary to “spot potential competitors” , explained Postma.
小题1:What did Erik Postma ask female participants to do in his study?
| A．To help collect the headshots of professional cyclists from the Tour de France. |
| B．To pick out the cyclists whom they are familiar with or appreciate most. |
| C．To rate the cyclists’ attractiveness according to facial appearance. |
| D．To predict the cyclists ’ performances based on facial appearance. |
| A．The more attractive a cyclist was, the better he performed in the race. |
| B．Generally, a cyclist’s endurance had nothing to do with his attractiveness. |
| C．Attractive cyclists proved to have less endurance than those who were less attractive. |
| D．Those who performed best in the games were considered more attractive than those who performed worst. |
| A．Women and men hold quite different views on male attractiveness. |
| B．Men with good looks tend to lie less popular than men with great endurance. |
| C．A man with great endurance appealed to women in ancient times and this remains the same today. |
| D．Most men don* t have the same ability as women to single out a good sportsman by simply looking at his face. |
最新试题
- 1冬半年我国大范围的强冷空气活动是（ ）A．台风B．寒潮C．梅雨D．沙尘暴
- 2某导体两端电压为3V时，导体中的电流是0.3A；如果将电压增大到6V，导体中的电流为______A；如果电压减小为1V，
- 3阅读下面的文言文，完成下面小题。仓慈字孝仁，淮南人也。始为郡吏。建安中，太祖开募屯田于淮南，以慈为绥集都尉。黄初末，为长
- 4下列地区与其住房、风俗习惯不相符的是[ ]A．黄土高原一窑洞一主食大米B．内蒙古草原一蒙古包一赛马C．西双版纳一
- 5如图，已知直线l与抛物线x2=4y相切于点P（2，1），且与x轴交于点A，O为坐标原点，定点B的坐标为（2，0）．（1）
- 6某地电话拨号入网有两种收费方式，用户可以任选其一．（一）计时制：0.05元/分；（二）包月制：50元/月（限一部个人住宅
- 7阅读下面文段，回答问题。 公与之乘，战于长勺。公将鼓之。刿曰：“未可。” 齐人三鼓。刿曰：“可矣。”齐师败绩。公将驰之
- 8（12分）下图为“我国东部某地区等高线地形图”（单位：m），读图，完成下列问题。（1）地形名称：（3分） B______
- 9已知分式x-2x+1的值为0，那么x的值为______．
- 10One day a famous speaker gave a speech to a crowd of people.
热门考点
- 1如图(a)所示电路中，当闭合开关后，两个电压表指针偏转均为图 (b)所示，则电阻R1两端的电压为_________，R2
- 22010年12月，巴西、俄罗斯、印度和中国一致决定，吸收南非加入“金砖国家”合作机制。目前，“金砖国家”的人口占世界总人
- 3青海省玉树地震发生后，宗教团体纷纷组织“宗教救援队”积极参与救灾，僧侣们还为在地震中的死难者超度祈祷，给震区的佛教信众很
- 4如图所示，在倾角为30°的足够长的斜面上有一质量为m的物体，它受到沿斜面方向的力F的作用。力F可按图（a）、（b）、（c
- 5北方地区指我国东部______以北的地区，面积约占全国的______%，人口约占全国的______%．南方地区指我国__
- 620世纪80年代以后，我国人口迁移的主要特点是[ ]A、人口的自发流动逐渐减少 B、流动人口数量呈逐年上升趋势
- 7（1）列举唐朝促进中外友好交往的人物。（2分）（2）在他们身上有什么优秀品质值得我们学习？（2分）（3）从中我们得到得什
- 8图中①、②分别是高空和近地面等压面，回答1～2题。小题1:图中a、b、c、d四处气压值最低的是A．aB．bC．cD．d小
- 9设函数f（x）的图象关于点（2，1）对称，且存在反函数f-1（x）．若f（5）=0，则f-1（2）的值是（ ）A．-1
- 10田纳西河流域实施梯级开发的有利影响是①有利于整个流域进行有效的防洪调度 ②提高了流域内的通航能力 ③为区域开发提供了充足