1.I have been trying to smoking.
A.give up B.pick up C.build up D.take up
2.Relief workers were by what they saw.
A.moved B.touched C.surprised D.worried
3.The weather is a constant of conversation in Britain.
A.question B.problem C.title D.topic
4.This is not of English,but is a feature of the Chinese language.
A.particular B.characteristic C.remarkable D.idiomatic
5.It is impossible to persuade him to apply for the job.
A.simply B.almost C.totally D.completely
6.These are defensive behavior patterns which from our fears.
A.stem B.rely C.develop D.grow
7.Only a small minority of the mentally ill are to harm themselves or others.
A.easy B.possible C.likely D.difficult
8.They have the to destroy the enemy in a few days.
A.possibility B.necessity C.ability D.probability
9.We have never seen such hills.
A.beautiful B.stretching C.spreading D.rolling
10.The leaves have been swept into heaps.
A.loads B.layers C.pyramids D.piles
11.The news will everyone.
A.attract B.terrify C.tempt D.excite
12.The article the major events of the decade.
A.described B.offered C.outlined D.presented
13.I won't that kind of behavior.
A.bear B.receive C.admit D.take
14.Their style of playing football is different.
A.barely B.scarcely C.hardly D.totally
15.Her sister her to apply for the job.
A.advised B.caused C.forced D.promised
1.A 2.C 3.D 4.B 5.B
6.A 7.C 8.C 9.A 10.D
11.B 12.C 13.A 14.D 15.A.
What do you know about the sea? We know that it looks very pretty when the sun is shining on it. We also know that it can be very rough when there is a strong wind. What other things do we know about it? The first thing to remember is that the sea is very big. When you look at the map of the world you will find there is more water than land. The sea covers three quarters of the world.
The sea is also very deep in some places. It is not deep everywhere. Some parts of the sea are very shallow. But in some places the depth of the sea is very great. There is one spot, near Japan, where the sea is nearly 11 kilometers deep! The highest mountain in the world is about 9 kilometers high. If that mountain were put into the sea at that place, there would be 2 kilometers of water above it! What a deep place!
If you have swum in the sea, you know that it is salty. You can taste the salt. Rivers, which flow into the sea, carry salt from the land into the sea. at that place, there would be 2 kilometers of water above it What a deep place!
If you have swum in the sea, you know that it is salty. You can taste the salt. Rivers, which flow into the sea, carry salt from the land into the sea. Some parts of the sea are saltier than other parts. There is one sea, called the Dead Sea, which is very salty. It is so salty that swimmers cannot sink! Fish cannot live in the Dead Sea!
In most parts of the sea, there are plenty of fishes and plants.4 Some live near the top of the sea. Others live deep down. There are millions of tiny living things that float in the sea. These floating things are so small that it is hard to see them Many fish live by eating these.
The sea can be very cold. Divers, who go deep down in the sea, know this. On the top the water may be warm. When the diver goes downwards, the sea becomes colder and colder. Another thing happens. When the diver goes deeper, the water above presses down on him. It squeezes him. Then the diver has to wear clothes made of metal. But he cannot go very deep. Some people who wanted to go very deep used a very strong diving ship! They went down to the deepest part of the sea in it. They went down to a depth of eleven kilometers!
1. The sea looks beautiful when it is calm.
A. Right B. Wrong C. Not mentioned
2. The land takes up 25% of the world.
A. Right B. Wrong C. Not mentioned
3. The sea is 6 kilometers in depth on average.
A. Right B. Wrong C. Not mentioned
4. The Dead Sea is so salty that nothing can live in it.
A. Right B. Wrong C. Not mentioned
5. The deeper one goes down in the sea, the fewer fishes and plants he can find.
A. Right B. Wrong C. Not mentioned
6. The deeper a diver goes down in the sea, the greater water pressure he bears.
A. Right B. Wrong C. Not mentioned
7. Divers have to use a very strong diving ship when they want to go down to the deepest part of the sea mainly because it is extremely cold here.
A. Right B. Wrong C. Not mentioned
1 Ford’s great strength was the manufacturing process--not invention.Long before he started a car company，he was a worker, known for picking up pieces of metal and wire and turning them into machines.He started putting cars together in 1 89 1, although it was by no means the first popular automobile，the Model T showed the world just how creative Ford was at combining technology and market.
2 The company’s assembly line alone threw America’s Industrial Revolution into overdrive (高速运转).Instead of having workers put together the entire car, Ford’s friends，who were great toolmakers from Scotland，organized teams that added parts to each Model T as it moved down a line.By the time Ford’s Highland Park plant was humming(嗡嗡作响)along in 1914，the world’s first automatic conveyor belt could turn out a car every 93 minutes.
3 The same year Henry Ford shocked the world with t11e$5-a day minimum Wage scheme.The greatest contribution he had ever made.The average Wage in the auto industry then was$2.34 for a 9-hour shift.Ford not only doubled that.he also took an hour off the workday.In those years it was unthinkable that a man could be paid that much for doing something that didn’t involve an awful lot of training or education.The Wall Street Journal called the plan “an economic crime”. And critics everywhere laughed at Ford.
4 But as the wage increased later to daily$10，it proved a critical component of Ford’s dream to make the automobile accessible(可及的)to a11 The critics were too stupid to understand that because Ford had lowered his costs per car，the higher wages didn’t matter--except for making it possible for more people to buy cars.
23 paragraph 1
24 paragraph 2
25 paragraph 3
26 paragraph 4
A Ford’s Followers
B The Assembly Line
C Ford’s Great Dream
D The Establishment of the Company
E Ford’s Biggest Contribution
F Ford’s Great Talent
27 The assembly line made it possible to
28 Ford was the first to adopt
29 Higher wages enabled many people to
30 Ford’s higher-wage and lower-cost strategy was strongly
A criticized by the media
B the low wage in the auto industry
C own a car
D Produce cars in large numbers
E the 8-hour-shift practice
F combined technology and market
Answers: 23.F 24.B 25.E 26.C 27.D 28.E 29.C 30.A.
Thirst for Oil
Werldwide every day，we devour the energyequivalent of about 200 million barrels of Oil.MoHt of the energy on Earth comes from the Sun.In fact enough energy from the Sun hits the planet’s surface each minute to cover our needs for an entire year，we just need to find an efficient way to use it.So far the energy in oil has been cheaper and easier to get at.But as supplies dwindle，this will change，and we will need to cure our addiction to oil.
Burning wood satisfied most energy needs until the steam-driven industrial revolution，when energy-dense coal became the fuel of choice.Coal is still used，mostly in power stations，to cover orle quarter of our energy needs，but its use has been declining since wc Staned
pumping up oil.Coal is the least efficient，unhealthiest and most environmentally damaging fossil fuel，but could make a comeback，as supplies are still plentiful;its reserves are five times larger than oil’s.
Today petroleum，a mineral oil obtained from below the surface of the Earth and used to produce petrol，diesel oil and various other chemical substances，provides around 40% of the world’s energy needs，mostly fuelling automobiles.The US consumes a quarter of all oil，and generates a similar proportion of greenhouse gas emissions.
The majority of oil Comes from the Middle East，which has half of known reserves.But other significant sources include Russia，North America，Norway，Venezuela and the North Sea.Alaska's Arctic National Wildlife Refuge1 could be a major new US source，to reduce reliance on foreign imports.
Most experts predict we will exhaust easily accessible reserves within 50 years，though opinions and estimates vary.We could fast reach an energy crisis in the next few decades，when demand exceeds supply. As conventional reserves become more difficuh to access.others such as oil shales and tar sands may be used instead.Petrol could also be obtained from coal.
Since we started using fossil fuels，we have released 400 billion tonnes2 of carbon，and burning the entire reserves could eventually raise world temperatures by 13℃.Among other horrors，this would result in the destruction of all rainforests and tile inching of all Arctic ice.
devour/di5vauE (r)/v.吞没，耗尽 dwindle/5dwindl/v.减少
dense/dens/adj.密集的 diesel oil 柴油
petrolcum/5petrEl/n.石油，原油 rainforest n.(热带)雨林
reliance/ri5laiEns/n.依赖，依靠 tar sand 沥青砂
oil shale 油页岩 destruction/dis5trQkFEn/n.破坏，毁灭
1. Alaska’s Arctic National Wildlife Refuge：美国阿拉斯加北极国家野生动物保护区。2001年，美国众议院通过了一项基于布什提出的在那里进行石油开采的议案。该议案遭到环境保护主义组织的反对。因此，目前在该区禁止开采石油。
2. tonnes：公吨(=1，000公斤)。不同于ton。 ton：在美国等于二千磅(=0.907公吨)，所以称作short ton：短吨。
1. “...we will need to cure our addiction to oil.” Why does the author say so?
A Most of the energy on Earth comes from the Sun.
B Oil supply is increasing all the time.
C Demand for oil is increasing all the time.
D Oil supply is decreasing.
2. Which of lhe following statements is NOT meant by the author，according to the second paragraph?
A Wood wets the fuel of choice before coal.
B The use of coal is declining.
C Coal is the most environmentally unfriendly fuel next to oil.
D Coal reserves are plentiful and will be likely to become the major fuel of choice..
3. Which country is the biggest consumer of petroleum?
A The United States.
4. What do experts say about the earth’s fuel reserves?
A The earth’s fuel reserves will be accessible for the next 50 years.
B There will soon be an energy crisis.
C Conventional reserves will soon become inaccessible.
D Fuel demand will decline.
5. What is NOT the result of consuming fossil fuels according to the last paragraph?
A Rainforests will be destroyed.
B Arctic ice will be melted.
C The earth’s temperature will be raised.
D The sea level will go up.
1. D 答案在第一段最后一句中。这里的xupplies指oil supplies。
2. C 短文的第二段告诉我们，木材曾经是主要燃料来源，然后被煤所替代;白人们开始采油后，对煤的需求下降了，但因为煤的储量远大于石油，它可能又会成为主要燃料，尽管它对环境最具破坏力。所以A、B、D均是作者的意思，而C不是。ncxt to oil除石油以外。
3. A 文章的第三段说，美国消耗全世界四分之一的石油。
4. B 答案在第五段第二句中。该段第一句说，地球上的燃料储量将在50年内耗尽，所以A不是正确选择;第三句的意思是，常规燃料的获取将变得困难，而不是不可获得，所以C也不是正确选择;D明显不是作者的意思。
5. D 选项A、B、I：都是最后一段中所表达的意思，所以D是正确选择。
Explorer of the Extreme Deep
Oceans cover more than two-thirds of our planet. Yet，just a small fraction of the undcrwaler world has been uxplored. Now，Scientists at the Woods Hole1 Oceanographic Institution (WHOI) in Massachusetts are building an underwater vehicle hat will carry explorers as deep as 6,500 meters (21,320 feet).The new machine，known as a manned submersible or human-operated vehicle (HOV)，will replace another one named Alvin2 which bas an amazing record of discovery，playing a key role in various important and famous undersea expeditions.Alvin has been operating for 40 years but can go down only 4,500 meters (14,784 feet).It’s about time for an upgrade，WHOI researchers say.
Alvin was launched in 1964.Since then，Alvin has worked between 200 and 250 days a year，says Daniel Fornari，a marine geologist and director of the Deep Ocean Exploration Institute at WHOI.During its lifetime，Alvin has carried some 12,000 people on a total of more than 3,000 dives. A newer，better versions of Alvin is bound to reveal even more surprises ahout a world that is still full of mysteries，Fornari says.It might also make the job of exploration a little easier.“We take so much for granted on land,” Fornari says.“We can walk around and see with our eyes how big things are. We can see colors，special arrangements.”
Size-wise，the new HOV will be similar to Alvin.It’ll be about 37 feet long.The setting area inside will be a small sphere，about 8 feet wide，like Alvin，it’ll carry a pilot and two passengers.It will be just as maneuverable.In most other ways，it will give passengers more opportunities to enjoy the view，for one thing.Alvin has only three windows，the new vehicle will have five，with more overlap so that the passengers and the pilot can see the same thing.
Alvin can go up and down at a rate of 30 meters every second，and its maximum speed is 2 knots (about 2.3 miles per hour)，while the new vehicle will be able to ascend and descend at 44 meters per second.It’ll reach speeds of 3 knots，or 3.5 miles per hour..
fraction/5frAkFEn/n.一部分 dive/daiv/v.& n.潜水;跳水
underwater/5QndE5wC:tE(r)/adj. bound/baund /adj.受约束的，一定的
maneuverable/mE5nu:vErEbl/adj. undersea/5QndEsi:/ adj.海底的
overlap /5EuvE5lAp/v.& n.重叠 upgrade/5Qp^reid/n.升级
ascend/E5send/ v.上升 geologist/dVi5ClEdVist/n.地质学家
1. Woods Hole：美国马萨诸塞州的一个渔村，但同时拥有许多重要研究机构，如：the Marine Biological Laboratory，the Sea Education Association以及the Woods Hole Oceanographic lnstitution。
1. What is Alvin?
A A research institute.
B A transporting vehicle.
C A submersible.
D A scientist.
2. Which of the following statements is NOT a fact about Alvin?
A h can carry explorers as deep as 6,500 meters.
B It has played a key role in various important undersea expeditions
C It was launched in the sixties of the twentieth century.
D It has been used for more than 40 years.
3. “...a world that is still full of mysteries” refers to
A the earth.
B out space.
C the ocean.
4. In what aspects are the new HOV and Alvin similar?
5. In what aspects are the new HOV and Alvin different?
A Offering better views.
D Both A and B..
1. C 短文第一段的第四、第五句提供了答案
2. A 文章第一段从第三句开始说，科学家正在研制一艘可将研究人员带到6 500米深处的潜水装置，而它将替代Alvin，因为Alvin只能潜到4 500米深处。A不是事实，所以是正确选择。
3. C 本文讨论探索海底世界的潜水装置，所以“充满神秘色彩的世界”指的就是海洋。
4. D 第三段的头三个句子告诉我们，HOV和Alvin在体积上和容量上相似。所以D是正确选择。
5. D 第三段最后两句告诉我们，Alvin只有三个窗户，而HOV有五个。最后一段告诉我们，两艘潜水装置的上下活动速度和行进速度有所差别。所以D是正确选择。
Scientists have been studying natural sources of methane for decades but hadn’t regarded plants as a producer，notes Frank Keppler，a geochem[st at the Max Planck Institute for Nuclear Physics in Heidelberg，Germany1.Now Keppler and his colleagues find that plants，from grasses to trees，may also be sources of the greenhouse gas.This is really surprising，because most scientists assumed that methane production requires an oxygen-free environment.
Previously，researchers had thought that it was impossible for plants to make significant amounts of the gas.They had assumed that，microbes2 need to be in environments without oxygen to produce methane.Methane is a greenhouse gas，like carbon dioxide.Gases such as methane and carbon dioxide trap heat in Earth’s atmosphere and contributeto global warming.
In its experiments，Keppler’s team used sealed chambers that contained the same concentration of oxygen that Earth’s atmosphere has.They measured the amounts of methane that were released by both living plants;and dried plant material，such as fallen leaves.
With the dried plants，the researchers took measurement at temperatures ranging from 30 degrees Celsius to 70 degrees C.At 30 degrees C，they found，a gram of dried plant material released up to 3 nanograms of methane per hour.(One nanogram is a billionth of a gram.) With every 10-degree rise in temperature，the amount of methane released each hour roughly doubled.
Living plants growing at their normal temperatures released as much as 370 nanograms of methane per gram of plant tissue per hour.Methane emissions tripled when living and dead plant was exposed to sunlight.
Beeause there was plenty of oxygen available，it’s unlikely that the types of bacteria that normally make methane were involved. Experiments on plants that weregrown in water rather than soil also resulted in methane emissions.That’s another strong sign that the gas came from the plants and not soil microbes.
The new finding is an “interesting observation,” says Jennifer Y.King，a biogeochemist at the University of Minnesota in St.Paul3.Because some types of soil microbes consume methane，they may prevent plant-produced methane from reaching the atmosphere.Field tests will be needed to assess the plant’s influence，she notes.
geochemist n.地球化学家 triple/5tripl/v.增加三倍;adj.三倍的
Celsius n.&.adj.摄氏(的) bacteria/bAk5tiEriE/n.(bacterium 的复数)细菌
microbe/5maIkrEJb/n.微生物 nanogram n.微克
biogeochemist n.生物地球化学家 chamber/5tFeimbE(r)/n.室，房间;腔
1. the Max Planck Institute for Nuclear Physics in Heidelberg，Germany：马克思·普朗克核物理研究所，位于德国海德堡。海德堡系德国西南部城市，在巴登一符腾堡州的内卡河畔。海德堡大学是德国历史最悠久的大学。
1. What was scientists understanding of methane?
A h was produced from plants.
B It was not a greenhouse gas.
C It was produced in oxygen-free environments.
D It traps more heat than any other greenhouse gas.
2. To test whether plants are a sot，roe of methane，the scientists created
A a oxygen-free environment.
B an environment with the same concentration of oxygen as the Earth has.
C a carbon dioxide-free environment.
D an environment filled with the greenhouse gas.
3. Which statement is true of the methane emissions of plants in the experiment?
A The lower the temperature，the higher the amount of methane emissions.
B I.iving plants release less methane than dried plants at the same temperature.
C When exposed to sunlight，plants stop releasing methane.
D The higher the temperature，the greater the amount of methane emissions.
4. Which of the following about methane is Not mentioned in the passage?
A Plants growing in soil release methane.
B Plants growing in water release methane.
C Soil microbes consume methane.
D Microbes in plants produce methane.
5. What is the beneficial point of some microbes consuming plant-produced methane?
A Methane becomes less poisonous.
B Methane is turned into a fertilizer.
C Less methane reaches the atmosphere.
D Air becomes cleaner.
1. C 短文的第一和第二段都讲到，科学家过去曾经认为，沼气必须在无氧的环境中才能产生。注意，作者用的是过去式：Most scientists assumed that...They had assumed that...。
2. B 第三段第一句说，科学家使用密封的房间来做实验，房间里氧气的浓度与地球大气中的氧气浓度相仿。所以B句符合原文的意思，其他三个选择则不符合原文内容。
3. D 根据第四和第五段的内容，只有D是正确的说法。温度越高沼气的释放量越高，有生命的植物释放的沼气远大于干植物的释放量，在阳光下，它们的沼气释放量是正常情况的三倍。
4. D 最后两段告诉我们，无论在土壤中还是在水中生长的植物都能释放沼气，土壤中的微生物消耗沼气，使沼气不至于进入空气。所以A、B、C的内容均符合短文最后两段中作者的意思。D的内容短文中没有提到。
5. C 最后一段的第二句可以找到本题的答案。.
The First Four Minutes
When do people decide whether or not they want to become friends? During their first four minutes together, according to a book by Dr. Leonard Zunin. In his book, "Contact: The first four minutes", he offers this advice to anyone __(1)___: "Every time you meet someone in a social situation, give him your undivided attention for four minutes. A lot of people’s whole lives would change if they did just that".
You may have noticed that the average person does not give his undivided attention to someone he has just met. He keeps looking over the other person’s shoulder, as if __(2)__. If anyone has ever done this to you, you probably did not like him very much.
When we are introduced to new people, the author suggests, we should try to appear friendly and self-confident. In general, he says, "People like people who like themselves".
On the other hand, we should not make the other person think we are too sure of ourselves. It is important to appear interested and sympathetic, realizing that the other person has his own needs, fears, and hopes.
Hearing such advice, one might say, "But I’m not a friendly, self-confident person. That’s not my nature. It would be dishonest for me to act that way".
In reply, Dr. Zunin would claim that a little practice can help us __(3)__. We can become accustomed to any changes we choose to make in our personality. "It is like getting used to a new car. It may be unfamiliar at first, but it goes much better than the old one."
But isn’t it dishonest to give the appearance of friendly self-confidence when we don’t actually feel that way? Perhaps, but according to Dr. Zunin, ’total honesty" is not always good for social relationships, especially during the first few minutes of contact. There is a time for everything, and a certain amount of play-acting may be best for the first few minutes of contact with a stranger. That is not the time to complain about one’s health or to mention faults one finds in other people. It is not the time to tell the whole truth about one’s opinions and impressions.
Much of __(4)__ also applies to relationships with family members and friends. For a husband and wife or a parent and child, problems often arise during their first four minutes together after they have been apart. Dr. Zunin suggests that these first few minutes together be treated with care. If there are unpleasant matters to be discussed, they should be dealt with later.
The author says that interpersonal relations should be taught as a required course in every school, along with reading, writing, and mathematics. In his opinion, success in life depends mainly on __(5)_. That is at least as important as how much we know.
A) Feel comfortable about changing our social habits
B) What has been said about strangers
C) How we get along with other people
D) Interested in starting new friendships
E) Hoping to find someone more interesting in another part of the room
F) Who are eager to make friends with everyone
Where Have All Our Visitors Gone?
Sixty years ago, a man named Kenneth Arnold saw something that people are still __1__ today -something that changed popular culture for ever.
Flying his plane over mountains in the US state of Washington, he saw a line of strange objects, either crescent -shaped or disc-like, flying __2__ the motion of a saucer skimming on water.
The media soon picked up on the story-the Flying Saucers were here1! Was the earth being. __3__ by creatures from another planet? Soon， so many sightings were made that the us military began to __4__. It called these strange objects UFO2s -Unidentified Flying Objects, and that is how they are __5__ today.
Military investigations found no evidence of visitors from outer space. But that did not stop the true __6__, The military were __7__ up, they said. Or __8__ it was because the travelers from space were of such superior intelligence that they could hide from the most sophisticated military analysts.
People have always seen strange lights in the sky. In the past these were explained in__9__ ways. In a world where religion was less influential and science fiction was popular, signs from god were replaced by visitors from other __10__.
The date of the first UFO signings was also significant. In 1947, World War II had just ended and the __11__ war was just beginning. Humanity seemed locked in endless conflicts. Like generations before them, people looked __12__ the skies for help. But instead of seeking God, they looked for help from super-intelligent aliens with __13__ technology. Belief in UFOs became the first religion of science.
However, even people who believe in UFOs are not quite sure why they visit the earth. The universe is a big place and it is __14__ to assume that there is life somewhere out there. It is possible that aliens have worked out how to travel through space. Yet some people report that they have been taken by aliens and have had experiments __15__ on them. Why would anyone travel across half the universe to conduct medical experiments on people living in small towns in the United States?.
crescent n.月牙，月牙形物 saucer n.碟
skim v.飞速掠过 alien n.外星人
1. A) looking B) seeing C) seeking D) feeling
2. A) below B) underneath C) with D) under
3. A) ruled B) bombarded C) captured D) visited
4. A) investigate B) attack C) shoot D) confront
5. A) named B) called C) known D) dubbed
6. A) believers B) thinkers C) followers D) liars
7. A) hiding B) covering C) cheating D) tricking
8. A) definitely B) undoubtedly C) necessarily D) maybe
9. A) awkward B) crude C) religious D) foolish
10. A) planets B) continents C) countries. D) regions
11. A) cool B) star C) nuclear D) cold
12. A) above B) to C) at D) up
13. A) traditional B) backward C) classical D) advanced
14. A) unthinkable B) impossible C) reasonable D) insensible
15. A) performed B) carried C) brought D) taken
1.B see和look这两个词词义相关， 因此首先重点关注。空格前面出现了动词saw(see的过去时态)， 因此 B是答案的可能性较大(提示1/常见考点1：考查上下文通过使用同一词汇/近义词/家祖词汇/反义词形成上下文意义的衔接)。Look是不及物动词，而see 既可用作及物动词也可用作不及物动词。空格处的动词是及物动词，引导定语从句的连接词充当从句中谓语动词的宾语，因此B是答案。
2.C 四个词都是介词。其中below、underneath和under是方位介词，这三个介词互为近义词，因此彼此排除掉(提示2：备选项中出现的近义词词组通常是干扰项)， 因此答案只能是with(with是方式介词)。With所在的句子结构说“...以碟子飞速掠过水面的移动方式飞着”。
3.D 选项D是文章主题词(visitors)的家族词汇，因此D可能是答案(提示3：文章主题词/文章主题词的近义词/文章主题词的家族词汇可能是答案)。第三段的第一句话(Military(军事的) investigations(调查) found(发现) no evidence(证据) of visitors(客人) from outer space(外层空间).)说“军事调查并没有发现证据，可以说明从外层空间来了客人了”， 由此判断空格处用visited上下文意义呼应。
4.A 空格处需要出现不及物动词，因此首先排除D(及物动词)。 该句说“不久由于出现了这么多的目击事件， 以至于美国军方开始...”, 根据该句句意判断A(调查)出现在空格中最恰当。也可根据第三段第一个句子中的 military investigations的线索选择investigate。
5.C name和call是近义词， 都可以表示“命名”，因此在“命名”这个词义上彼此排除掉，name虽然还有“任命， 提名”这样的词义，但这样的词义放入空格中意义不通(空格所在的句子结构说“那就是现在它们(不明飞行物)怎样被...的”)，因此A和B都不是答案。剩下的选项中选项C(了解)放入空格中意义通顺(那就是不明飞行物怎样被人们知道的)， 因此答案为C。
7.B 只有cover可以跟up搭配。因此选择covering。Cover up是固定搭配，其含义为“掩盖”。.