The term e-commerce refers to all commercial transactions conducted over the Internet, including transactions by consumers and business-to-business transactions. Conceptually, e-commerce does not (1) from well-known commercial offerings such as banking by phone, "mail order" catalogs, or sending a purchase order to supplier (2) fax. E-commerce follows the same model (3) in other business transactions; the difference (4) in the details.
To a consumer, the most visible form of e-commerce consists (5) online ordering. A customer begins with a catalog of possible items, (6) an item, arranges a form of payment, and (7) an order. Instead of a physical catalog, e-commerce arranges for catalogs to be (8) on the Internet. Instead of sending an order on paper or by telephone, e-commerce arranges for orders to be sent (9) a computer network. Finally, instead of sending a paper representation of payment such as a check, e-commerce (10) one to send payment information electronically.
In the decade (11) 1993, e-commerce grew from an (12) novelty to a mainstream business influence. In 1993, few (13) had a web page, and (14) a handful allowed one to order products or services online. Ten years (15) , both large and small businesses had web pages, and most (16) users with the opportunity to place an order. (17) , many banks added online access, (18) online banking and bill paying became (19) . More importantly, the value of goods and services (20) over the Internet grew dramatically after 1997.

（8）（）

A:visible B:responsible C:feasible D:sensible

可见语言(visible speech)

Scientists can’t yet make an invisibility cloak like the one that Harry Potter uses. But, for the first time, they’ve constructed a simple cloaking device that makes itself and something placed inside it invisible to microwaves.
When a person "sees" an object, his or her eye senses many different waves of visible light as they bounce off the object. The eye and brain then work together to organize the sesensations and reconstruct the object’s original shape. So, to make an object invisible, scientists have to keep waves from bouncing off it. And they have to make sure the object casts no shadow. Otherwise, the absence of reflected light on one side would give the object away.
Invisibility isn’t possible yet with waves of light that the human eye can see. But it is now possible with microwaves. Like visible light, microwaves are a form of radiant energy. They are part of the electromagnetic spectrum, which also includes radio waves, infrared light, ultraviolet rays, X rays, and gamma rays. The wave lengths of microwaves are shorter than those of radio waves but longer than those of visible light.
The scientists’ new "invisibility device" is the size of a drink coaster and shaped like a ring. The ring is made of a special material with unusual ability. When microwaves strike the ring, very few bounce off it. Instead, they pass through the ring, which bends the waves all the way around until they reach the opposite side. The waves then return to their original paths.
To a detector set up to receive microwaves on the other side of the ring, it looks as if the waves never changed their paths as if there were no object in the way! So, the ring is effectively invisible.
When the researchers put a small copper loop inside the ring, it, too, is nearly invisible. However, the cloaking device and anything inside it do cast a pale shadow. And the device works only for microwaves, not for visible light or any kind of electromagnetic radiation. So, Harry Potter’s invisibility cloak doesn’t have any real competition yet.
What is true of microwaves

A:Their wave lengths are shorter than those of visible light. B:Their wave lengths are longer than those of visible light. C:They are different from visible light as they are a kind of radiant energy. D:They are visible to the human ey

Scientists can’t yet make an invisibility cloak like the one that Harry Potter uses. But, for the first time, they’ve constructed a simple cloaking device that makes itself and something placed inside it invisible to microwaves.
When a person "sees" an object, his or her eye senses many different waves of visible light as they bounce off the object. The eye and brain then work together to organize the sesensations and reconstruct the object’s original shape. So, to make an object invisible, scientists have to keep waves from bouncing off it. And they have to make sure the object casts no shadow. Otherwise, the absence of reflected light on one side would give the object away.
Invisibility isn’t possible yet with waves of light that the human eye can see. But it is now possible with microwaves. Like visible light, microwaves are a form of radiant energy. They are part of the electromagnetic spectrum, which also includes radio waves, infrared light, ultraviolet rays, X rays, and gamma rays. The wave lengths of microwaves are shorter than those of radio waves but longer than those of visible light.
The scientists’ new "invisibility device" is the size of a drink coaster and shaped like a ring. The ring is made of a special material with unusual ability. When microwaves strike the ring, very few bounce off it. Instead, they pass through the ring, which bends the waves all the way around until they reach the opposite side. The waves then return to their original paths.
To a detector set up to receive microwaves on the other side of the ring, it looks as if the waves never changed their paths as if there were no object in the way! So, the ring is effectively invisible.
When the researchers put a small copper loop inside the ring, it, too, is nearly invisible. However, the cloaking device and anything inside it do cast a pale shadow. And the device works only for microwaves, not for visible light or any kind of electromagnetic radiation. So, Harry Potter’s invisibility cloak doesn’t have any real competition yet.
Harry Potter’s invisibility cloak doesn’t have any real competition yet, because ______.

A:scientists have not found out how his cloak works B:the cloaking device is a total failure C:the cloaking device works only for microwaves D:the cloaking device works only for visible light

? ?阅读下面的短文，文中有15处空白，每处空白给出了4个选项，请根据短文的内容从 4个选项中选择1个最佳答案。

A:unknown B:interesting C:different D:visible

下面有3篇短文，每篇短文后有5道题，每题后面有4个选项。请仔细阅读短文并根据短文回答其后面的问题，从4个选项中选择1个最佳答案。
{{B}}第一篇{{/B}}

What is true of microwaves?

A:Their wavelengths are shorter than those of visible light. B:Their wavelengths are longer than those of visible light. C:They are different from visible light as they are a kind of radiant energy. D:They axe visible to the human eye.

Dark Forces Dominate Universe The earth．moon．sun and all visible stars in the sky make up less than one percent of the universe．Almost all the rest is dark matter and dark energy，unknown forces that ______(51)astronomers． Observations in recent years have changed the basic______ (52)of how the universe evolved and have indicated how little is known about the major forces and substances that______ (53) our world Astronomers now know that luminous(发光的)matter—stars，planets and hot gas----Accounts ______ (54) only about 0,4 percent of the universe．Non-luminous components，such as black holes and intergalactic(星系间的)gas，______ (55)up 3.6 percent The rest is either dark matter , about 23 percent，or dark energy，about 73 percent． Dark matter．Sometimes ______ (56)“cold dark matter，”has been known for some time．Only recently have researchers come to understand the key role it ______ (57)formation of stars，planets and even people． We ______ (58) our very existence to dark matter,” said physicist Paul Steinhardt and a co-author of a review on dark matter which ______ (59)not long ago in the journal Science． “Dark matter dominated the structure (60)in the early universe，”Steinhardt said．’’For the first few billion years dark matter contained most of the mass of the universe You can think of ordinary matter (61) a froth(泡沫)of an ocean of dark matter．The darkmatter dumps(结成块)and the ordinary matter falls into it．That (62) to the formation of the stars and galaxies(星系)．”Without dark matter ,“ there would be virtually no structures in the universe The nature of dark matter is ______ (63)It cannot be seen or detected directly Astronomers know it is there because of its______ (64)on celestial(天体的)objects that can be seen and measured． But the most dominating force of all in the universe is called dark energy, a recently ______ (65)power that astronomers say is causing the galaxies in the universe to separate at a faster and faster speed.

A:unknow B:interesting C:different D:visible

　第三篇 　　Small But Wise 　　On December 14, NASA1 blasted a smallbut mighty telescope into space. The telescope is called WISE and is about aswide around as a trashcan. Don’t let its small size fool you: WISE has apowerful digital camera, and it will be taking pictures of some the wildestobjects2 in the known universe,including asteroids, faint stars, blazing galaxies3 and giant clouds of dustwhere planets and stars are born. 　　“I’mvery excited because we’re going to be seeing parts of the universe that wehaven’t seen before, ” said Ned Wright, a scientist who directs the WISEproject. 　　Since arriving in space, the WISEtelescope has been circling the Earth, held by gravity in a polar orbit4( thismeans it crosses close to the north and south poles with each lap5). Its camerais pointed outward, away from the Earth, and WISE will snap a picture of adifferent part of the sky every 11 minutes. After six months it will have takenpictures across the entire sky. 　　The pictures taken by WISE won’t be likeeveryday digital photographs, however. WISE stands for “Wide-field InfraredSurvey Explorer. ” As its name suggests, the WISE camera takes pictures offeatures that give off infrared radiation6. 　　Radiation is energy that travels as awave. Visible light, including the familiar spectrum of light7 that becomesvisible in a rainbow, is an example of radiation. When an ordinary digitalcamera takes a picture of a tree, for example, it receives the waves of visiblelight that are reflected off the tree. When these waves enter the camerathrough the lens, they’re processed by the camera, which then puts the imagetogether. 　　Waves of infrared radiation are longerthan waves of visible light, so ordinary digital cameras don’t see them, andneither do the eyes of human beings. Although invisible to the eye, longerinfrared radiation can be detected as warmth by the skin. 　　That’s a key idea to why WISE will beable to see things other telescopes can’t. Not everything in the universe showsup in visible light. Asteroids, for example, are giant rocks that float throughspace — but they absorb most of the light that reaches them. They don’t reflectlight, so they’re difficult to see. But they do give off infrared radiation, soan infrared telescope like WISE will be able to produce images of them. Duringits mission WISE will take pictures of hundreds of thousands of asteroids. 　　Brown dwarfs8 are another kind ofdeep-space object that will show up in WISE’s pictures. These objects are“failed” stars — which means they are not massive enough to jump start9 thesame kind of reactions that power stars such as the sun. Instead, brown dwarfssimply shrink and cool down. They’re so dim that they’re almost impossible tosee with visible light, but in the infrared spectrum they glow. It is truethat infrared radiation.

A:is not detectable to humans. B:looks brighter than visible light. C:is visible light reflected off an object. D:has longer waves than thoseof visible light.

The term e-commerce refers to all commercial transactions conducted over the Internet, including transactions by consumers and business-to-business transactions. Conceptually, e-commerce does not (51) from well-known commercial offerings such as banking by phone, "mail order" catalogs, or sending a purchase order to supplier (52) fax. E-commerce follows the same model (53) in other business transactions; the difference (54) in the details.
To a consumer, the most visible form of e-commerce consists (55) online ordering. A customer begins with a catalog of possible items, (56) an item, arranges a form of payment, and (57) an order. Instead of a physical catalog, e-commerce arranges for catalogs to be (58) on the Internet. Instead of sending an order on paper or by telephone, e-commerce arranges for orders to be sent (59) a computer network. Finally, instead of sending a paper representation of payment such as a check, e-commerce (60) one to send payment information electronically.
In the decade (61) 1993, e-commerce grew from an (62) novelty (新奇事物) to a mainstream business influence. In 1993, few (63) had a web page, and (64) a handful allowed one to order products or services online. Ten years (65) , both large and small businesses had web pages, and most provided users with the opportunity to place an order. Besides, many banks added online access, and online banking and bill paying became widespread. More importantly, the value of goods and services acquired over the Internet grew dramatically after 1997.

A:visible B:sensible C:feasible D:responsible

Questions from 36 to 40 are based on the following passage: In addition to visible trade, which involves the import and export of goods, there is also invisible trade, which involves the exchange of services between countries. Transportation service across national boundaries is an important kind of invisible trade. International transportation involves different means of transport such as ocean ships, planes, trains, trucks and inland water vessels. However, the most important of them is maritime ships. When an export arranges shipment, he generally books space in the cargo compartment of a ship or charters a whole vessel. Some countries such as Greece and Norway have large maritime fleets and earn a lot by way of this invisible trade. Insurance is another important kind of invisible trade. In the course of transportation, a cargo is vulnerable to many risks such as collision, pilferage, fire, storm, exploration, and even war. Goods being transported in international trade must be insured against loss or damage. Large insurance companies provide service for international trade and earn fees for other nations’ foreign trade. Lloyd’s of London is a leading exporter of this service. Tourism is yet another important form of invisible trade. Many countries may have beautiful scenery, wonderful attractions, places of historical interest, or merely a mild and sunny climate. These countries attract large numbers of tourists, who spend money for traveling, hotel accommodations, meals, taxis, and so on. Some countries depend heavily on tourism for their foreign exchange earnings, and many countries are making great efforts to develop their tourism. The fourth type of invisible trade meriting attention is called immigrant remittance. This refers to the money sent back to home countries by people working in a foreign land. Import and export of labor service may be undertaken by individuals, or organized by companies or even by states. And this is becoming an important kind of invisible trade for some countries. Invisible trade can be as important to some countries as visible trade is to others. In reality, the kinds of trade nations engage in are varied and complex, often a mixture of visible and invisible trade.

According to the meaning of the passage, China at present engages mostly in（）.

A:visible trade B:invisible trade C:combination of the two D:commodity trade