题目
题型：不详难度：来源：
Now, scientists in California say they have come up with a way to turn a living cell into a memory device.
It can store only one tiny bit of information, but it’s a start. In the future, a cell-based gadget might travel through the body and record measurements. The benefit to human health could be big: the right tool, for example, might record the earliest signs of disease.
Doctors, scientists and other curious people want to know what is happening inside the body, even at levels that can’t be seen by the naked eye. So far, there is no device small enough to travel through the bloodstream.
If normal machines won’t do the trick, perhaps biology will. Scientists who work in the field of synthetic (合成的) biology are trying to find ways to turn living things into human tools. In the case of the new memory device, bioengineers from Stanford University used the genetic material inside living cells to record information.
This genetic material consists of DNA. Found in nearly every cell, DNA carries all of the information that keeps a living thing alive.
In the new experiment, the researchers turned DNA from bacteria(细菌) into a switch. They “flip (翻转)” a small section of DNA. Then, using the same procedure (过程) , the scientists flip the section again—returning it into its normal structure.
Using these DNA switches, “We can write and erase DNA in a living cell,” bioengineer, Jerome Bonnet, explained to Science News.
It might take years before his team or others identity whether a DNA-based memory device might be practical. Right now, it takes one hour to complete a flip. That is far too long to be useful. Plus, a flipped section has a very small little memory—less than what a computer uses to remember a single letter.
“This was an important proof that it was doable,” Bonnet told Science News. “Now we want to build a more complex system, something that other people can use.”
小题1:What is the aim of listing the electronic things in the first paragraph?
| A．To make the passage more fashionable. |
| B．To show how electronic things have memory. |
| C．To discuss things in detail. |
| D．To make the subject of the text more understandable. |
| A．To detect disease at the earliest point. |
| B．To help improve the memory. |
| C．To help people build a body. |
| D．To replace many electronic gadgets. |
A. The cells of bacteria.
B. The DNA of bacteria.
C. A section of bacteria.
C. The nucleus of bacteria.
小题4:What do we know about a flipped section of DNA?
| A．It has a very small memory. |
| B．It can function as a computer. |
| C．It has one letter in it. |
| D．It takes a day to complete it. |
答案
小题1:D
小题2:A
小题3:B
小题4:A
解析
试题分析：本文主要介绍了科学家已经成功把活细胞植入了记忆装置以及现在科学家正在研究细菌的DNA。
小题1:推断题。第一自然段列举电子事物的目的是使得这篇文章的主题更容易理解，故选D。
小题2: 细节题。根据It can store only one tiny bit of information, but it’s a start. In the future, a cell-based gadget might travel through the body and record measurements. The benefit to human health could be big: the right tool, for example, might record the earliest signs of disease.可知它的好处在于可以早期发现疾病，故选A。
小题3:细节题。根据In the new experiment, the researchers turned DNA from bacteria(细菌) into a switch. They “flip (翻转)” a small section of DNA. Then, using the same procedure (过程) , the scientists flip the section again—returning it into its normal structure.可知正在被研究的物体是细菌的DNA，故选B。
小题4: 细节题。根据That is far too long to be useful. Plus, a flipped section has a very small little memory—less than what a computer uses to remember a single letter.故选A。
核心考点
试题【Every electronic gadget (小玩意) needs good memory. A music player stores songs, al】；主要考察你对题材分类等知识点的理解。[详细]
举一反三
“There is a between the studies chosen by young Danes and their background. Even for the young people who have very good grades in their A-level exams, and who could successfully admission to a large variety of studies, the parents’ of education and social class play an important role in their choice,” says Education Sociologist Jens Peter Thomsen, who is one of the researchers behind the study.
The study “The Educational Strategies of Danish University Students from Professional and Working-Class Backgrounds” is 60 interviews with Danish students from six different university level study programmes: Medicine, architecture, sociology, economy, pharmacy and business studies.
The young people bring with them the they get from their families. If you grow up in a home with parents who are doctors or architects with a strong professional , it is an obvious choice to follow the path as your parents when you grow up.
“For young people whose parents are university educated, such as fame and mastery of expert knowledge are important. They are by an educational culture in which you are a diligent student, and where leisure activities are to the identity that lies within your studies. These young people have also grown up with discussions around the dinner table which also prepare them for their lives as students,” says Jens Peter Thomsen.
He also added, “Young people who come from a working class background, and have good grades have to the full range of opportunities they have. But the effort to reach this goal must start early”.
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At the moment, there are two reliable ways to make electricity from sunlight. You can use a panel of solar cells to create the current directly, by liberating electrons from a semiconducting material such as silicon. Or you can concentrate the sun’s rays using mirrors, boil water with them, and employ the steam to drive a generator.
Both work. But both are expensive. Gang Chen of the Massachusetts Institute of Technology and Zhifeng Ren of Boston College therefore propose an alternative. They suggest that a phenomenon called the thermoelectric（热电）effect might be used instead—and they have built a prototype（原型）to show that the idea is practical.
Thermoelectric devices are not new. They are used, for example, to capture waste heat from car engines. They work because certain materials generate an electrical potential difference within themselves if one part is hotter than another. That can be used to drive a current through an external circuit.
The reason thermoelectric materials have not, in the past, been applied successfully to the question of solar power is that to get a worthwhile current you have to have a significant temperature difference. (200℃ is considered a good starting point.) In a car engine, that is easy. For sunlight, however, it means concentrating the heat in some way. And if you are going to the trouble of building mirrors to do that, you might as well go down the steam-generation route, which is a much more efficient way of producing electricity. If the heat concentration could be done without all the equipment of mirrors, though, thermoelectricity’s inefficiency would be balanced by the cheapness of the equipment.
In their view, three things are needed to create a workable solar-thermoelectric device. The first is to make sure that most of the sunlight which falls on it is absorbed, rather than being reflected. The second is to choose a thermoelectric material which conducts heat badly but electricity well. The third is to be certain that the temperature gradient（梯度）which that badly conducting material creates is not wasted by poor design.
小题1:The following methods can be adopted to make electricity from sunlight EXCEPT .
| A．putting a panel of solar cells into use |
| B．concentrating sun’s rays with mirrors |
| C．creating a solar-thermoelectric device |
| D．building a practical solar prototype |
| A．Because it’s hard for them to build enough mirrors to make it work. |
| B．Because 200℃ was hard to reach at that time even in a car engine. |
| C．Because of the failure of having a significant temperature difference. |
| D．Because it was hard to focus the sun’s rays with equipment of mirrors. |
| A．Thermoelectric Device --- the Best Method of All |
| B．A New Method of Making Electricity from Sunlight |
| C．How to Create a Workable Thermoelectric Device |
| D．Solar Power --- a New Energy Trend in the Future |
It doesn’t kill germs better than cooler water, but turning tap temperatures high, the US burns carbon equal to the emissions of Barbados.
People typically wash their hands seven times a day in the United States, but they do it at a far higher temperature than is necessary to kill germs, a new study says. The energy waste is equivalent to the fuel use of a small country.
It’s cold and flu season, when many people are concerned about avoiding germs. But forget what you think you know about hand washing, say researchers at Vanderbilt University. Chances are good that how you clean up is not helping you stay healthy; it is helping to make the planet sick.
Amanda R. Carrico, a research assistant professor at the Vanderbilt Institute for Energy and Environment in Tennessee, told National Geographic that hand washing is often “a case where people act in ways that they think are in their best interest, but they in fact have inaccurate beliefs or outdated perceptions.”
Carrico said, “It’s certainly true that heat kills bacteria, but if you were going to use hot water to kill them it would have to be way too hot for you to tolerate.”
She explained that boiling water, 212°F (99.98°C), is sometimes used to kill germs - for example, to clean drinking water that might be polluted with germs. But “hot” water for hand washing is generally within 104°F to 131°F (40°C to 55°C.) At the high end of that range, heat could kill some germs, but the sustained contact that would be required would scald the skin.
Carrico said that after a review of the scientific literature, her team found “no evidence that using hot water that a person could stand would have any benefit in killing bacteria.” Even water as cold as 40°F (4.4°C) appeared to reduce bacteria as well as hotter water, if hands were scrubbed, rinsed（冲洗）and dried properly.
In fact, she noted that hot water can often have an unfavorable effect on hygiene. “Warmer water can harm the skin and affect the protective layer on the outside, which can cause it to be less resistant to bacteria,” said Carrico.
Using hot water to wash hands is therefore unnecessary, as well as wasteful, Carrico said, particularly when it comes to the environment. According to her research, people use warm or hot water 64 percent of the time when they wash their hands. Using that number, Carrico’s team calculated a significant impact on the planet.
“Although the choice of water temperature during a single hand wash may appear minor, when multiplied by the nearly 800 billion hand washes performed by Americans each year, this practice results in more than 6 million metric tons of CO2 equivalent emissions annually,” she said.
That’s roughly equal to the emissions of two coal-fired power plants, or 1,250,000 passenger vehicles, over the course of a year. It’s higher than the greenhouse gas emissions of small countries like El Salvador or Armenia, and is about equivalent to the emissions of Barbados. If all US citizens washed their hands in cooler water, it would be like eliminating the energy-related carbon emissions of 299,700 US homes, or the total annual emissions from the US zinc or lead industries.
The researchers found that close to 70 percent of respondents said they believe that using hot water is more effective than warm, room temperature, or cold water, despite a lack of evidence backing that up, said Carrico. Her study noted research that showed a “strong cognitive（认知的） connection” between water temperature and hygiene in both the United States and Western Europe, compared to other countries, like Japan, where hot water is associated more with comfort than with health.
The researchers published their results in the July 2013 issue of International Journal of Consumer Studies. They recommended washing with water that is at a “comfortable” temperature, which they noted may be warmer in cold months and cooler in hot ones.
小题1:What does the writer mainly focus on when writing this passage?
| A．Whether hot water helps kill germs effectively in hand washing. |
| B．How hot water contributes to the serious worsening of our planet. |
| C．Why the consumption of hot water is unnecessary and wasteful. |
| D．What the advantages and disadvantages of using hot water are. |
| A．burn | B．improve | C．soften | D．wrinkle |
| A．two coal-fired power plants | B．US zinc or lead industries |
| C．1,250,000 passenger vehicles | D．El Salvador or Armenia |
A. Boiling water at 212°F (99.98°C) works effectively in killing germs.
B. Warmer water can damage the protective layer of the outside skin.
C. There is much difference between cold water and hot water in reducing bacteria.
D. Americans have inaccurate beliefs or outdated perceptions in hand washing.
小题5:Which of the following is the standard of a comfortable water temperature for washing hands?
A. Warmer in winter and cooler in summer.
B. Between 104°F to 131°F (40°C to 55°C).
C. Below 104°F (40°C) or above 131°F (55°C).
D. Warm enough to kill germs and clean up.
小题6: If you want to read stories of this kind afterwards, which of the following magazines will you probably subscribe to?
| A．Universal Science Fiction | B．Science & Discoveries |
| C．Environment & Protection | D．Exploration of America |
GOOD DAD:A man whose wife has died with a young family and a busy job as a lawyer, Gregory Peck"s character in the 1962 film is one of the great heroes of American cinema Firm but fair he teaches his children respect and human decency（正派)．Harper Lee"s novel gets a respectable transposition（转变)to film, thanks to Gregory Peck"s perfect performance.
Jack Torrance in The Shining
BAD DAD: When Jack Torrance ,his wife ,Wendy ,and son, Danny ,escaped from the cold winter to the Overlook Hotel we know that Jack has hardly been a model father But when Jack becomes extremely angry and tries to murder his family with an axe, Danny used his intelligence to defeat him and left him to freeze to death．
George Bailey in It"s a Wonderful life
GOOD DAD: James Stewart"s character is a father-of-four who is saved from the edge of suicide (自***)and realizes his positive effect on others lives．Much of the film is unpleasant, with George shouting at his children as he faces financial problems. But finally the lovable father realizes the worth of his own life, the value of friendship and the importance of being a loving dad
Darth Vader in The Empire Strikes Back（帝国大厦）
BAD DAD: When the unfriendly cyborg（半机器人）told Luke Skywalker that he was his father ,the son"s reaction says it all: "No! No!" It"s hardly a joyful welcome to the family. For most of his son"s life, Darth Vader has been an absent dad—and he has just cut off Luke"s hand You can understand why Father"s Day cards might not be available.
小题1:Who is Harper Lee?
| A． An actor. | B． A novelist | C． A movie director. | D． A translator. |
| A． Jack Torrance | B． Wendy | C． Danny | D． Darth Vader |
| A．To kill a Mockingbird | B．The Shining |
| C．It"s a Wonderful Lift | D．The Empire Strikes Book |
| A．He lost his hand in an accident |
| B．His father changed him into a cyborg. |
| C．He discovered that he had a cruel father: |
| D．His father lived with him for most of his life. |
If you go to sleep on your back, you’re a very open person. You normally trust people and you are easily influenced by fashion or new ideas. You don’t like to displease people. So you never express your real feelings. You’re quite shy and you aren’t quite sure of yourself.
If you sleep on your stomach, you are a rather secretive person. You worry a lot and you’re always easily upset. You always stick to your own opinions or judgment, but you don’t raise your hopes too much. You usually live for today not tomorrow. This means that you enjoy having a good time.
If you sleep curled up, you are probably a very nervous person. You have a low opinion of yourself and so you’re often defensive. You’re shy and you don’t normally like meeting people. You prefer to be on your own. You’re easily hurt.
If you sleep on your side, you have usually got a well—balanced personality. You know your strengths and weakness. You’re usually careful. You believe in yourself. You sometimes feel anxious, but you don’t often get sad. You always insist on what you think even if it makes people rather angry.
小题1:According to the passage, a person, who is not willing to change his mind and hard to deal with, probably sleeps .
| A．on his side | B．on his back | C．curled up | D．on his stomach |
| A．do things personally. | B．stay alone |
| C．keep things secret | D．trust others easily |
| A．The people sleeping on their stomachs and those sleeping on his backs. |
| B．The people sleeping on their sides and those sleeping curled up. |
| C．The people sleeping on their backs and those sleeping on their sides. |
| D．The people sleeping curled up and those sleeping on their stomach. |
| A．one’s sleeping position has something to do with one’s character. |
| B．everyone has got both real and secret personalities. |
| C．the position in which one goes to sleep is the most important one. |
| D．when awake, one does not show one’s secret personality. |
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