The color red often means danger --- and by paying attention, accidents can be p
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The color red often means danger --- and by paying attention, accidents can be prevented. At railroad crossings, flashing red fights warn cars to stay back. A red light at a traffic crossing tells cars to stop, so they don"t run into other cars.
In the future, the color red also may help prevent danger at construction sites. Thanks to new work by engineers, bridge supports --- or other kinds of materials --- could one day contain a color-changing material. It will turn red before a structure collapses(倒塌) or falls apart.
The secret behind the color-changing material is a particular type of molecule(分子). Molecules come in all shapes and sizes, and make up everything you can see, touch or feel. How a molecule behaves depends on what kinds of atoms(原子) it contains, and how they"re held together.
To get a rough picture of one way atoms are held together in a molecule, imagine you and your friends standing in a large circle, holding hands. Each person represents one atom, your clasped hands represent the bond, and the entire circle represents a molecule.
The molecule being used to turn the material red is called mechanophore(机械响应性聚合物). When one chemical bond in the mechanophore molecule breaks, the rest of the molecule turns red.
There is a way to get rid of~ the red color: light. When a bright light is shone on the mechanophore, the broken bond is fixed and the red color disappears. This "self-healing" may be a problem for engineers who want to use the color-changer in big construction projects that will be outside, in the sunlight. And if bright light keeps the red color from appearing, then the mechanophore"s warning system will be useless.
Scientists still have a lot of work to do before the color-changing molecules can be used outside the lab. If mechanophore can be used in the real world, they are suggested to be employed in a new kind of paint.
小题1:The first paragraph mainly tells us __________.| A．the color red is widely used in our life | | B．how to prevent car accidents | | C．the color is an important signal of warning | | D．how to use color red |
小题2:The color red will be used at construction sites to _________.| A．tell different materials used in the building | | B．warn people that the building is dangerous | | C．make the building more beautiful | | D．tell people the building is under construction |
小题3:The example given in the fourth paragraph is to show _________.| A．the way atoms are held together in a molecule | | B．how a molecule behaves in an object | | C．how to play an old game | | D．how people get along with each other |
小题4:What can make the mechanophore’s warning system ineffective?| A．Paints | B．Water | C．Poor building materials | D．The bright light |
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答案
小题1:C
小题2:B
小题3:A
小题4:D |
解析
试题分析：文章介绍了一种新型的建筑材料，可以在大楼危险的时候，变化成红色，从而警告人们当心，但是这种材料也有缺点，研究人员还要做大量的研究工作。
小题1:段落大意题：从第一段的句子：The color red often means danger可知这段讲的是颜色是一个很重要的警告信号，选C
小题2:细节题：从文章第二段的句子：In the future, the color red also may help prevent danger at construction sites.可知建筑工地的红色警告人们这个建筑是危险的，选B
小题3:细节题：从第四段的句子；To get a rough picture of one way atoms are held together in a molecule, 可知这个例子是为了表明在分子里面原子是怎么组合的，选A
小题4:细节题：从第六段的句子：When a bright light is shone on the mechanophore, the broken bond is fixed and the red color disappears.可知使机械响应性聚合物失效的是明亮的颜色，选D |
举一反三
When Armida Armato’s daughter, Alexia, came home from school one day last year keen to go on a school trip to Ecuador, she wasn’t too sure how to feel. She was happy that her daughter could experience something she never did as a teen but was fearful of letting her travel to such a remote part of the world.
Alexia was 16 at the time, a student at Westwood High School. The school sponsored a humanitarian trip for 26 students and two teachers to spend 18 days living in a mountain village to build a one-room school. Even though Armato trusted her daughter, the other students and the teachers, she was worried about the side effects from the travel vaccines, possible accidents, and medical care.
Now that Alexia was home, Armato said she saw her daughter’s new maturity, greater confidence and independence. “This is the best thing I ever did,” Alexia said. “The experience was so eye-opening and life-changing. You’re with people who are not as lucky as you are. They live in very poor conditions but they’re so happy and outgoing. You say, ‘My God. I’m taking everything for granted back home.’”
She said they built a one-room school from scratch with no mechanical cement mixers. They used their hands, shovels and basic tools. She and another student lived with a local family in a small village about eight hours outside the capital, Quito. Despite the initial strangeness and knowing only basic Spanish, she said they grew very close and felt like a family.
Every year, groups of students at Montreal High School like Alexia pack their bags and fly off with classmates and teachers to developing countries where they volunteer for a variety of projects.
“Armato’s worries are very common among parents,” says Bill Nevin, a teacher at St. George’s High School. He organizes a humanitarian rip to India to the Sheela Bal Bhavan orphanage and says the three biggest fears families have are health, security and contact.
小题1:When hearing the news that her daughter would go on a school trip to Ecuador, Armato was _______.| A．proud and happy | B．supportive but concerned | | C．fearful and nervous | D．excited but puzzled |
小题2:The underlined phrase “from scratch” in Paragraph 4 probably means “______”.| A．having great help | B．using high technology | | C．ending up in failure | D．starting from the beginning |
小题3:What would be the best title for the text?| A．Volunteering helps students grow and develop. | | B．School trips make parents worried about their children. | | C．Ecuador is the most attractive travel destination in the world. | | D．Brave Alexia dreams to work in Ecuador one day. |
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Until recently, the "science of the future" was supposed to be electronics and artificial intelligence. Today it seems more and more likely that the next great breakthroughs in technology will be brought through a combination of those two sciences with organic chemistry and genetic engineering. This combination is the science of biotechnology.
Organic chemistry enables us to produce marvelous synthetic materials. However, it is still difficult to manufacture anything that has the capacity of wool to conserve (保存) heat and also to absorb moisture. Nothing that we have been able to produce so far comes anywhere near the combination of strength, lightness and flexibility that we find in the bodies of ordinary insects.
Nevertheless, scientists in the laboratory have already succeeded in "growing" a material that has many of the characteristics of human skin. The next step may well be "biotech hearts and eyes" which can replace diseased organs in human beings. These will not be rejected by the body, as is the case with organs from humans.
The application of biotechnology to energy production seems even more promising. In 1996 the famous science fiction writer, Arthur C. Clarke, many of whose previous predictions have come true, said that we may soon be able to develop remarkably cheap and renewable sources of energy. Some of these power sources will be biological. Clarke and others have warned us repeatedly that sooner or later we will have to give up our dependence on non-renewable power sources. Coal, oil and gas are indeed convenient. However, using them also means creating dangerously high levels of pollution. It will be impossible to meet the growing demand for energy without increasing that pollution to catastrophic (灾难性的) levels unless we develop power sources that are both cheaper and cleaner.
It is attempting to think that biotechnology or some other "science of the future" can solve our problems. Before we surrender to that temptation we should remember nuclear power. Only a few generations ago it seemed to promise limitless, cheap and safe energy. Today those promises lie buried in a concrete grave in a place called Chernobyl, in the Ukraine. Biotechnology is unlikely, however, to break its promises in quite the same or such a dangerous way.
小题1:According to the passage, the science of the future is likely to be ________.| A．electronics | B．biotechnology | | C．genetic engineering | D．nuclear technology |
小题2:The materials produced with organic chemistry are ________.at present.| A．as good as wool | | B．as good as an insect"s body | | C．better than natural materials | | D．not as good as natural materials |
小题3:According to the passage, it may soon be possible ________.| A．to transplant human organs | | B．to make artificial hearts and eyes | | C．to produce drugs without side effects | | D．to make something as good as human skin |
小题4:In 1996, Arthur C. Clarke predicted that_______.
A. the Chernobyl disaster would happen in two years
B. we will never stop using non-renewable power sources biological
C. oil, gas and coal could be repeatedly used in the future
D. power sources would be put into use soon
小题5:What do we learn from the last paragraph?| A．Biological power will keep all its promises. | | B．Biological power is cheaper than nuclear power. | | C．Biotechnology can solve all our future energy problems | | D．Biological power may not be as dangerous as nuclear power |
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It has been argued by some that gifted children should be grouped in special classes. The __ __ has been on the belief that in regular classes these children are held back in their intellectual (智力的) growth by learning situation that has designed for the children.
There can be little doubt that classes can help the gifted children to graduate earlier and take their place in life sooner. However, to take these out of the regular classes may create serious problems.
Many are concerned that gifted children become and lose interest in learning. However this concern is more often from parents and teachers than from students, and some of these simply conclude that special classes should be set up for those who are talented. Some top students do feel bored in class, but why they so goes far beyond the work they have in school. Studies have shown that to be bored is to be anxious. The gifted child who is bored is an child.
| 小题1: | | A．principle | B．theory | C．arguement | D．classification |
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| 小题2: | | A．smart | B．poor | C．mature | D．average |
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| 小题3: | | A．regular | B．special | C．small | D．creative |
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| 小题4: | | A．children | B．programs | C．graduates | D．designs |
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| 小题5: | | A．doubted | B．bored | C．worried | D．tired |
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| 小题6: | | A．students | B．adults | C．scholars | D．teachers |
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| 小题7: | | A．believe | B．think | C．say | D．feel |
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| 小题8: | | A．outstanding | B．intelligent | C．anxious | D．ordinary |
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Pilling a cat can be a "terrible” experience. Cats don’t want something pushed down their throats, and they’ll fight with all their strength to prevent it. In fact, it’s amazing how powerful their small bodies can be.
The easiest way of pilling a cat is to press the pill into powder. Then mix the powder with a small amount of wet food. If your cat usually eats dry food, she will probably view the wet food as a treat and eat it up.
If your cat won’t eat the wet food that contains the pill or if she is too ill to eat, you can get a “pill gun”. There are some basic instructions. Getting your cat’s mouth to open is going to be the most difficult part. First, be sure the pill is in a handy place. Then you can put your cat on a bookshelf with her bottom in a corner or you can put her on your lap firmly tied. Have your cat facing to the right if you’re right-handed. With your left hand, hold your cat at the cheekbones, putting your palm (手掌) at the top of her head. Keeping your finger off the trigger (扳机), with your right hand, Insert the pill gun until the pill is positioned over the tongue and open throat Be sure to give your cat a treat directly after giving the pill.
If you don’t feel comfortable using a pill gun, you can try giving the pill by hand. Push your cat’s head backwards just far enough so that her nose is pointing towards the ceiling. At this point, most cats will slightly open their mouths. With the little finger or ring finger of the hand holding the pill, open the bottom jaw a little more. You may need to hold her top jaw with your other hand while doing this. Aim straight and lightly throw the pill or drop it. Most cats will then swallow the pill.
小题1:Pilling a cat can be a terrible experience because cats ______.| A．are amazingly powerful and dangerous | | B．may fight with all their strength against pills | | C．refuse something pressed down their throats | | D．are difficult to treat once they’ve got ill |
小题2:Which of the following statements is true according to the second paragraph?| A．Wet food with medicine is usually a treat to cats. | | B．Cats used to dry food must reject wet food. | | C．The easiest pilling is to press the pill into powder. | | D．Cats arc most likely interested in something new. |
小题3:Using a “pill gun”, you had better hold your cat ______ if you’re left-handed.| A．facing to the right | B．with your right hand | | C．at the head | D．on your lap firmly |
小题4:A cat probably opens its mouth naturally when ______.| A．its nose is straight upwards | B．it is touched by fingers | | C．its head is turning around | D．it is served with its favorite pills |
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Will online courses transform world of education?
Some may wonder what it feels like to attend a class at Stanford University. The recently popular MOOCs (Massive Open Online Courses) can satisfy this desire. But they are also most likely to change the situation of higher education. Only last month，both Peking University and Tsinghua University announced plans to start open online course on the edX platform，one of the world’s major providers of MOOCs，to explore this new form of online education.
Gaining momentum(势头)
“It’s not only a change of platforms from offline to online. It’s more about a reform of
teaching methods，even the whole education system，”said Chen Jining，president of Tsinghua University.
The potential of MOOCs to reform education has been obvious in the US ever since the immediate popularity of the course Artificial Intelligence，taught by Stanford University professor Sebastian Thrun, who later co-founded Udacity, a platform with 1.6 million enrolled(注册) students in 200 countries. According to Nature magazine，by June 2013，74 percent of universities in the US offered some type of online course. Lu Fang, vice-president of Fudan University，explains the appeal of MOOCs as a simple case of supply and demand：“The demand for high quality educational resources from both enrolled students and professionals is feeding the rise of MOOCs，in which classes usually taught by top teachers are available to everyone，”said Lu.
Too early to replace
With easy access and free of charge, MOOCs are said to have the potential to change the present education system. But there are barriers，because hardly any universities offer degree certificates, as college administrators point out, it’s difficult to confirm if students are foaming anything in MOOCs，reposed USA Today．
The Wall Street Journal also reposed that，presently，a typical MOOC student is likely to have
already graduated from college and is using the course to explore an interest or acquire professional
skills. Even so, an increasing number of undergraduates are signing up.
“What we are really establishing(创建)are educational pathways for people who want skills that are related to contemporary jobs，”Thrun told The Wall Street Journal．
小题1:MOOCs have been considered likely to reform education since___________．| A．the founding of Udacity | | B．the wide application of online education | | C．the popularity of the course Artificial Intelligence | | D．the opening of MOOCs on the edX platform in China |
小题2:According to Lu Fang, MOOCs have become popular because___________．| A．high quality educational resources are in demand | | B．students can attend courses in famous universities | | C．college students have access to famous teachers | | D．MOOCs have brought about revolution in education |
小题3:What can we learn from the passage?| A．Most of the MOOCs focus on professional training for college graduates． | | B．There are barriers for MOOCs to replace the present education system． | | C．International companies prefer applicants who graduate from MOOCs． | | D．More and more undergraduates have realized the limits of MOOCs． |
小题4:The author’s attitude towards MOOCs is___________．| A．doubtful | B．negative | C．critical | D．optimistic |
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