题目内容

In a unique research cooperation between Stratasys, Education, R&D departments and MIT’s Self-Assembly Lab, a new process is being developed, known as 4D Printing.

The 4D printing concept, which allows materials to “self-assemble (自行组装)” into 3D structures, was initially proposed by Massachusetts Institute of Technology faculty member Skylar Tibbits. Tibbits and his team combined a strand (缕) of plastic with a layer made out of “smart” material that could self-assemble in water. They advanced this concept by creating materials that can change into several different complicated shapes, though this kind of material remains the bottleneck of 4D technology.

To many people that are just starting to get used to the idea of 3D printers, the name 4D is causing confusion because they cannot understand where this fourth “dimension” coming from. 4D technology shares many of the same principles of 3D printing and is essentially still about creating a new, 3D structure out of certain component; however, Tibbits states the fourth dimension at work here comes from concept of the fourth dimension of time. The difference between these 3D and 4D creations is that these new forms have the ability to transform and adapt over time.

4D printing works through self-assembly — a system where “disordered elements form an “ordered” structure via an interaction. With these 4D printed materials, these disordered materials are strands or sheets of specially designed materials. Environmental changes then stimulate (刺激)a response from them so that they form a preprogrammed shape.

The idea of having adaptable technology that only relies on energy and non-human interactions raises some interesting questions about where 4D printing can be used and the practical applications in dangerous environments. This could mean improved infrastructures in extreme conditions, leading to a reduced need for workers to put themselves at risk, but the potential goes even further than that. The technology promises exciting new possibilities for a variety of applications. A solar panel or similar product could be produced in a flat shape onto which functional devices can be easily installed. It could then be changed to a compact shape for packing and shipping. After arriving at its destination, the product could be stimulated to form a different shape that serves its function. Also it could be used to build furniture, bikes, cars and even buildings. As with many of the ideas being put forward, it is easy to go a step too far into the extreme, but this just shows the potential of 4D in comparison to 3D.

The next stage for the research is to move from printing single strands to sheets and eventually whole structures. And water need not be the process ’ s only energy source.

1.Which of the following displays the fourth dimension of 4D printing?

A. 4D printing creates a new, 3D structure out of certain component.

B. 4D technology reduces need for workers to put themselves at risk.

C. 4D technology can be used in many more fields than 3D printing.

D. 4D printed materials reshape themselves with conditions changing.

2.The major problem concerning the development of 4D printing lies in__________.

A. producing essential 4D printers

B. creating proper smart materials

C. providing a suitable environment

D. promoting practical applications

3.What does the passage lead you to believe?

A. 4D printing will take the place of 3D printing in the near future.

B. Most aspects of our daily life can be affected by 4D printing.

C. 4D printing will benefit humans by saving labor somehow.

D. Smart materials can be transformed into other types of material.

4.It can be inferred from the passage that__________.

A. electricity is not used in 4D technology

B. 4D printing has been applied in industry

C. more potential of 4D is to be discovered

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America is growing older.Fifty years ago, only 4 out of every 100 people in the United States were 65 or older.Today, 10 out of every 100 Americans are over 65.The aging of the population will affect American society in many ways — education, medicine, and business.Quietly, the graying(老龄化)of America has made us a very different society — one in which people have a quite different idea of what kind of behavior is suitable at various ages.

A person’s age no longer tells you anything about his / her social position, marriage or health.There’s no longer a particular year in which one goes to school or goes to work or gets married or starts a family.The social clock that kept us on time and told us when to go to school, get a job, or stop working isn’t as strong as it used to be.It doesn’t surprise us to hear of a 29-year-old university president or a 35-year-old grandmother, or a 70-year-old man who has become a father for the first time.Public ideas are changing.

Many people say, "I am much younger than my mother-or my father- was at my age." No one says "Act your age" anymore.We’ve stopped looking with surprise at older people who act in youthful ways.

1.It can be learned from the text that the aging of the population in America ______.

A.has made people feel younger

B.has changed people’s social position

C.has changed people’s understanding of age

D.has slowed down the country’s social development

2.The underlined word ‘one’ refers to _______.

A.a society

B.America

C.a place

D.population

3."Act your age" means people should _______.

A.be active when they are old

B.do the right thing at the right age

C.show respect to their parents young or old

D.take more physical exercises suitable to their age

4.If a 25-year-old man become general manager of a big firm, the writer of the text would most probably consider it _______.

A.normal

B.wonderful

C.unbelievable

D.unreasonable

阅读下面材料,在空白处填人适当的内容(1个单词)或括号内单词的正确形式,并将答案填写在答题卡相应的位置上。

Two weeks before Christmas,two little girls were walking down the street1.t hey saw old Harry,who was on his knees pulling weeds from around a tree. He wore a pair of worn gloves.His fingers were sticking out 2.the ends,blue from the cold. They stopped to talk to him.

Harry told them he 3.(get) the yard in shape as a Christmas gift for his mother,who had died several years before.“My mother was all I had. She loved her yard and trees,so I do this for her every Christmas."

His -words touched the girls and soon they 4.(join) him,pulling weeds. When they finished,Harry pressed a coin into each of their hands.“I wish I could pay you more,but that's all rve got right now,”he said.

The girls had often passed his house,and they remembered that it had always been 5. poor condition. No decorations to add cheeriness were anywhere in sight.

As they walked on,the coin in one little girl's hand seemed to burn a hole of 6.(guilty).The next day she called her friends7.they agreed to put their coins in a jar marked“Harry's Christmas Gift".Then they began to seek out small jobs to earn more.Every coin they earned went into the jar.

Finally,they had enough 8.(buy)new gloves. Christmas Eve found them on Harry's

doorstep singing carols. They presented him with the gloves. With9.(tremble)hands,he held the gloves to his face and wept. No doubt he once again felt10.love of others as the girls reached out to him.

“Image is everything.” An entire industry has been built upon the assumption that image is everything, but when it comes down to it, an appealing image is not enough. If there is no substance(事实) behind the image, the product, service or person will fail eventually.

First of all, one should consider how important image is in the selling of products and services. Advertising agencies have raised the art of creating an image to a state of near perfection. Public concept of that product or service is certainly managed by the images created by the advertising agencies. But if the product or service does not live up to the image that was created, the customer will be very dissatisfied and possibly ask for their money back. For example, the Arthur Andersen accounting firm had spent decades building up an image of trustworthiness. But the recent scandal (丑闻) showed that behind that image, it cheated in business practices. Despite the previous positive image, the firm is being accused of criminal actions and it will probably not survive as a business unit. Although the image had been nearly perfect, the reality behind the image has led to the downfall of the world famous accounting firm.

Similarly, personal advisers can build up a public image for politicians and movie stars. Putting out positive news releases, making sure that only the best photographs are published, and ensuring that the person is seen in all the right places can build up a very positive image in the view of the general commons. But once again, history is filled with examples of both politicians and movie stars that fell from grace like the story of the Hollywood actor giving in to the pressures of fame and fortune. With people, just as with products and services, image is certainly important, but without positive substance behind the image, failure is close.

To summarize, it is clear that an appealing image is extremely important to success, whether that image is related to selling a product or service or to the “selling” of a person. But image is only half of the equation. What lies behind that image is every bit as important as the image itself —— the person or product must deliver on that image or there is little chance for long-term success.

1.The downfall of the Arthur Andersen accounting firm is due to ________.

A. its previous images

B. its dishonesty in business

C. its bad management

D. its poor service

2.Why did some famous people fall from grace?___________

A. Their images were not well built up

B. They felt much pressure from the public.

C. They failed to live up to their images

D. They paid little attention to fame and fortune.

3.The structure of the passage is ________.

A: Argument P: Point C: Conclusion

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