1.We have to ask them to quit talking in order that all people present could hear us clearly.
A) decrease B)cease
C) continue D)keep
2. They had a far better yield than any other farm miles away around this year.
A) goods B) soil
C) climate D) harvest
3. The city has decided to do away with all the old buildings in its center.
A) get rid of B) set up
C) repair D) paint
4.During the past ten years there have been dramatic changes in the international situation.
A) permanent B) powerful
C) striking D) practical
5. Since the Great Depression, the United States government has protected farmers from damaging drops in grain prices.
A) slight B) surprising C) sudden D) harmful
6. Cement was seldom used in building the Middle Ages.
A) crudely B) rarely C) originally D)occasionally
7. There is an abundant supply of cheap labor in this country.
A) a steady B) a plentiful C) an extra D) a stable
8. The most crucial problem any economic system faces is how to use its scarce resources.
A)puzzling B) difficult C) terrifying D) urgent
9. We derive knowledge mainly from books
A)deprive B) obtain
C) descend D)trace
10.We all consider him a man of dynamic personalities.
A)dangerous B) doubtful
11. The room was furnished with the simplest essentials, a bed, a chair, and a table
A)supplied B) gathered
12. The local government decided to merge the two firms into a big one.
A)motivate B) combine
13. He emphasized a feasible plan which can be accepted by the both sides.
A)favorable B) possible
14. When does the next train depart?
A)pull up B) pull down
C)pull out D)pull in
15. Because administering the whole company, he sometimes has to work around the clock.
A)adjusting B) evaluating
1 B。划线词和四个被选项这5个动词都是C级应该掌握的常见词汇。其中除A以外，其余的被选项都可以跟动名词结构：quit doing.. = cease doing./停止..., continue doing./继续.., keep doing./一直…。该句的含义是“我们得要求他们停止说法以便所有在场的人都能清楚地听见我们的声音。”
2. D。分析：在该句中yield 是用作名词(因为该词的前面有不定冠词a)，分析：抓住句子中与划线部分相关的结构或用词特点：能与不定冠词a搭配使用的被选项只有C和D(气候，倾向， 风气，如：a mild climate温和的气候)。再借助句子中其他特征词：farm，判断harvest“收成”是答案。该句含义是“这一年中他们的收成要比数英里以外的其他任何农场的收成都好得多。”Yield: vt, vi出产, (常与to连用)放弃;投降;让步 n. 产量;收成
3.A。分析：划线短语是动词短语，对于该短语的语义有两种查找方法：1。利用动词do，直接在字典中查找do away with 这个短语的语义。不难得出该短语的语义是“去掉”，所以A是答案;2。利用该短语中的词义推测：away是“离开”，而备选项中： set up是“建立”， repair是“修理”， paint 是“油漆, 描绘”，都与“离开”无关，所以只有get rid of是答案。该句句意是“这座城市已经决定把位于市中心的所有的旧的建筑物都废弃掉。”
4.C. 分析：根据画线词的家族词(drama)的本义和与画线词搭配的结构的含义(“变化”)，判断C是答案。该句含义是“在过去的十年中，在国际形式方面已经出现了显著的变化。”Striking: adj. 引人注意的;显著的;Dramatic: adj. 戏剧的;有关戏剧的; 引人注目的。
5. D。分析：根据构词法：划线词的前部分是 damage(破坏)，即damaging是动词damage的分词，所以推测该词义大概是“破坏的” 。而备选答案都是常见词汇，其中只有harmful是“破坏的”，因此可以推断harmful是答案。该句含义是“从经济大萧条以后，美国政府一直在(采取措施)使农民避免遭受到由于粮食价格的下降而带来的损失”。
6. B。分析：seldom是常见词汇，该词义是“很少地” 。而备选答案中rarely也是常见的否定副词，是“很少地”。该句含义是“水泥在中世纪的建筑中很少使用。”
7.B。分析：steady 和stable是近义词，都可表示“稳定的”， 所以可以相互排除掉。再根据构词法：plentiful = plenti(y) + ful 判断B的含义是“大量的”。借助句意“在这个国家里有大量的廉价劳动力”判断B最合适。
8.D。分析：crucial“至关紧要的”和 urgent“紧急的”含义最接近。该句句意是“任何经济体系所面临的最至关紧要的的问题是如何使用它稀少的资源”。Puzzling adj.(使)迷惑的, (使)为难的; terrifying adj.使感到恐怖的;
9. B. 分析：根据句意(我们主要从书本上获得知识)判断B(获得)是答案。Deprive vt.剥夺, 使丧失; descend vi.下来, 下降; trace n.痕迹, 踪迹, 微量vt.描绘,追踪
10.C.分析：该句含义是“我们都认为他是一个个性很活跃的人。”dynamic adj.动力的,动态的，生气勃勃的; active adj.积极的,现行的, 活动的, 活跃的;doubtful adj.可疑的, 不确的; easy adj.容易的, 舒适的, 宽裕的, 从容的adv.不费力的, 轻松
11. A。 分析：根据划线词后的介词搭配(with)判断答案A。furnish..with..= supply/provide..with./给..提供..; gather n.集合, 聚集vi.集合, 聚集vt.使聚集; grasp
vt/ n.抓住,掌握, 领会;该句含义是“这个房间配备了最基本的物品：一张床，一把椅子，和一张桌子。”
12. B。 分析：借助句意(当地的政府决定把两家公司合并成一家公司)判断B((使)联合)是答案。Motivate v.激发; compact adj.紧凑的, 紧密的, 简洁的; nominate vt.提名, 推荐, 任命
13. B。 分析：该句含义是“他强调要制定出一个能够被双方都接受的可行计划” 。
feasible adj.可行的, 切实可行的; favorable adj.赞成的, 有利的, 赞许的;genuine adj.真实的, 真正的
14. C。 分析：depart vi.离开, 起程， 该词和C是近义词。pull out v.拔出, 离开; pull up
v.拔起, 停下; pull down v.摧毁, ****, 使降低; pull in v.进站, 靠岸
15. D。 分析：借助句意(因为管理着整个公司，他有时候得夜以继日地工作)判断D(管理)是答案。Evaluate vt.评价, 估计; adjust vt.调整, 调节, 校准; engage vt.使忙碌， 使从事于, 使参加 vi.答应, 从事
Why is the Native Language Learnt So Well
How does it happen that children learn their mother tongue so well? When we compare them with adults learning a foreign language, we often find this interesting fact. A little child without knowledge or experience often succeeds in a complete mastery of the language. A grown-up person with fully developed mental powers, in most case, may end up with a faulty and inexact command. What accounts for this difference?
Despite other explanations, the real answer in my opinion lies partly in the child himself, partly in the behavior of the people around him. In the first place, the time of learning the mother tongue is the most favorable of all, namely, the first years of life. A child hears it spoken from morning till night and, what is more important, always in its genuine form, with the right pronunciation, right intonation, right use of words and right structure. He drinks in all the words and expressions, which come to him in a flash, ever-bubbling spring. There is no resistance: there is perfect assimilation.
Then the child has, as it were, private lessons all the year round, while an adult language-student has each week a limited number of hours, which he generally shares with others. The child has another advantage: he hears the language in all possible situations, always accompanied by the right kind of gestures and facial expressions. Here there is nothing unnatural, such as is often found in language lessons in schools, when one talks about ice and snow in June or scorching heat in January. And what a child hears is generally what immediately interests him. Again and again, when his attempts at speech are successful, his desires are understood and fulfilled.
Finally, though a child's " teachers " may not have been trained in language teaching, their relations with him are always close and personal. They take great pains to make their lessons easy.
1. Compared with adults learning a foreign language, children learn their native language with ease.
A. Right B. Wrong C. Not mentioned
2. Adults' knowledge and mental powers hinder their complete mastery of a foreign language.
A. Right B. Wrong C. Not mentioned
3. The reason why children learn their mother tongue so well lies solely in their environment of learning.
A. Right B. Wrong C. Not mentioned
4. Plenty of practice in listening during the first years of life partly ensures children's success of learning their mother tongue.
A. Right B. Wrong C. Not mentioned
5. A child learning his native language has the advantage of having private lessons all the year round.
A. Right B. Wrong C. Not mentioned
6. Gestures and facial expressions may assist a child in mastering his native language.
A. Right B. Wrong C. Not mentioned
7. So far as language teaching is concerned, the teacher's close personal relationship with the student is more important than the professional language teaching training he has received.
A. Right B. Wrong C. Not mentioned
1. A。问题句说“与学习外语的成年人相比，儿童学习母语很容易。”。该问题是明显考察对事实的判断。利用答案线索词：adult和 children。于是我们很快在第1段的段首句中发现children， 而在随后的一句中发现adult。研究这两段的语义：前一句说“为什么孩子学习他们的母语学得这么好?”，后一句接着说“当我们把孩子和学习外语的成年人比较时，我们发现了这个有趣的事实。”，依据这两句判断该问题句实际上是对原文中这两个句子的总结说明。有时有的问题是考察考生的语言总结能力。
2. C。问题句说“成年人的知识和智力阻碍了他们对外语的掌握。”。该问题是也是明显考察对事实的判断。利用答案线索词：mental powers。于是我们很快在第1段的第3句中发现mental powers，发现该句说“智力充分发展的成年人，在大多数的情况下，对外语的掌握是错误的和不准确的。”。而该句的下一句引出的是成年人和儿童在学习语言方面不同的理由(第2段的段首句)，但原文中并没提到“成年人掌握外语的能力较差的原因”，所以判断该问题句“没提到”。
4. A。问题句说“早年大量的听力练习是儿童成功地学习母语的一个原因。”。利用答案线索词：the first years of life。于是我们很快在第2段的第2句中发现相关句。该句说“早年学习母语的时间是最有益的。”。接下来的一句突出的说明了儿童期听力练习的形式。所以判断该问题句的说法“正确”。
5. B。问题句说“儿童学习母语的优势是可以常年上私人辅导课。”。借助常识判断该句的说法不正确。利用答案线索词：all the year round。于是我们很快在第3段的第1句中发现直接相关句。比较原句和问题句的结构，发现不同之处在于“as it were”的结构。当心：部分结构的差异往往是设置了陷阱。 实际上，as it were的含义是“仿佛是”。所以原文说“仿佛是”，而问题句说“是”，所以判断问题句“不正确”。
6. A。问题句说“手势和面部表情可能会对儿童掌握母语有帮助。”。利用答案线索词：Gestures and facial expressions。于是我们很快在第3段的第2句中发现直接相关句。该句说“儿童学习母语的另一个优势是可以接触各种情景的母语，而且母语中还伴随了正确的手势和面部表情。”。可见原句的说法与问题句一致，所以判断问题句“正确”。
阅读下面这篇短文，短文后有2项测试任务：(1)1---4 题要求从所给的6个选项中为第2--5 段每段选择1个正确的小标题;(2)第5--8题要求从所给的6个选项中选择4个正确的选项，分别完成每个句子。请将答案涂在答题卡相应的位置上。
Did you know that before 1950, hurricanes had no names? They were simply given numbers. The first names were simply Alpha, Bravo, Charlie, etc. but in 1953, females names were given because of the unpredictability (不可预知) factor of the storms. In 1979, realizing the sexist (性别歧视的) nature of such names, the lists were expanded to include both men and women.
Hurricanes and typhoons (台风) are the same things. If they form in the Atlantic, we call these strong storms hurricanes, from the West Indian word hurricane, meaning "big wind." And if they are Pacific storms, they are called typhoons from the Chinese taifun, meaning " great wind." To be classified as a hurricane, the storm must have maximum winds of at least 75 mph. These storms are big, many hundreds of miles in diameter.
Hurricanes get their power from water vapor as it gives out its stored-up energy. All water vapor gives out heat as it condenses (凝结) from a gaseous state to a liquid state over fixed points on the equator (赤道). To make a hurricane, you must have extremely wet, warm air, the kind of air that can only be found in tropical region.
Scientists have determined that the heat given out in the process of water condensation can be as high as 95 billion kilowatts per hour. In just one day alone, the storm can produce more energy than many industrialized nations need in an entire year! The problem is that we don't know how to make sure such great energy work for us.
Predicting the path of a hurricane is one of the most difficult tasks for forecasters. It moves at a typical speed of 15 mph. But not always. Some storms may race at twice this speed, then suddenly stop and remain in the same location for several days. It can be maddening (发疯的) if you live in a coastal area that may be hit.
The biggest advance in early detection is continuous watch from weather satellites. With these, we can see the storms form and track them fully, from birth to death. While they can still kill people and destroy property, hurricanes will never surprise any nation again.
1. Paragraph 1_________ A. A short history of naming hurricanes
B. Harnessing the hurricane energy
2. Paragraph 2 _________C. Difficulty in forecasting the course of a hurricane
D. Huge energy stored in a hurricane
3. Paragraph 4__________E. Forecasting a hurricane through satellite watching
F. Different names for the same things
4. Paragraph 5 ___________
5. Both male and female names are used for hurricanes in consideration of _____________.
6. Using weather satellites can ensure _____________ of hurricanes.
7. Energy specialists may be interested in _____________ of hurricanes.
8. Scientists cannot accurately predict the course of a hurricane due to _____________.
A. the timely (及时的) discovery
C. sex equality
D. its connection with humans
E. the huge power
F. its uncertainty
2.F.除了选项F以外，其余选项中的核心词(如：harness, forecast, store, satellite)在文章中均没有出现。
The biggest advance in early detection is continuous watch from weather satellites. With these, we can see the storms form and track them fully, from birth to death.
第1篇 Medical Journals
Medical journals are publications that report medical information to physicians and other health professionals.
In the past，these journals were available only in print.With the development of electronic/publishing，many medical journals now have Web sites on the Internet，and some journals/publish only online.A few medical journals，like the Journal of the American Medical Association，are considered general medical journals because they cover many fields of medicine.Most medical journals are specialty journals that focus on a particular area of medicine.
Medical journals/publish many types of articles.Research articles report the results of research studies on a range of topics varying from the basic mechanisms of diseases to clinical trials that compare outcomes of different treatments.Review articles summarize and analyze the information available on a specific topic based on a careful search of the medical literature.
Because the results of individual research studies can be affected by many factors，combining results from different studies on the same topic can be helpful in reaching conclusions about the scientific evidence for preventing，diagnosing or treating a particular disease.Case conferences and case reports may be/published in medical journals to educate physicians about particular illnesses and how to treat at them.Editorials in medical journals are short essays that express the views of the authors，often regarding a research or review article/published in the same issue.
Editorials provide perspective on how the current article fits with other information on the same topic.Letters to the editor provide a way for readers of the medical journal to express comments， questions or criticisms about articles/published in that journal.
1. The main readers of medical journals are
A)the general public.
2. Which of the following statements is NOT true?
A) Many medical journals also/publish online.
B)A few medical journals are general medical journals.
C)Most medical journals/publish only online.
D)Most medical journals are specialty journals.
3. How many major types of articles are mentioned in the passage?
4. An article dealing with results from different studies on the same topic is called
A)a research article.
B)a review article.
C)a case report.
5.Letters to the editor enable readers of a medical journal to express comments on
A)any medical event.
B) articles/published in the same issue.
C)articles/published in that journal
第2篇 Ford Abandons Electric Vehicles
The Ford motor company’s abandonment of electric cars effectively signals the end of the road for the technology，analysts say.
General Motors。and Honda’ceased production of battery.powered cars in 1 999, to focus on fuel cell and hybrid electric gasoline engines, which are more attractive to the consumer.Ford has now announced it will do the same.
Three years ago.the company introduced the Think City two—seater car and a golf cart called the THINK, or Think Neighbor.It hoped to sell 5，000 cars each year and 10，000 carts.But a lack of demand means only about l，000 of the cars have been produced，and less than 1。700 carts have been sold so far in 2002.
“The bottom line is we don’t believe that this is the future of environment transport for the mass market.”Tim Holmes of Ford Europe said on Friday.“We feel we have given electric our best shot”
The Think City has a range of only about 53 miles and up to a six-hour battery recharge time.General Motors’EVI electric vehicle also had a limited range。of about 100 miles.
The very expensive batteries also mean electric cars cost much more than petrol-powered alternatives.An electric Toyot~RAV4 EV vehicle costs over$42，000 in the US, compared with just $17，000 for the petrol version.Toyota and Nissan…are now the only major auto manufacturers to produce electric vehicles.
“There is a feeling that battery electric has been given its chance.Ford now has to move on with its hybrid program“，and that is what we will be judging them on，”Roger Higman，a senior transport campaigner at UK Friends of the Earth，told the Environment News Service.
Hybrid cars introduced by Toyota and Honda in the past few years have sold well.Hybrid engines Offer Greater mileage than petrol—only engines , and the batteries recharge themselves. Ford says it thinks such vehicles will help it meet planned new guidelines“on vehicle emissions” in the U.S.
However,it is not yet clear exactly what those guidelines will permit.In June，General Motors and Daimler Chrysler won a court injunction，delaying by two years Californian legislation requiring car—makers to offer 100，000 zero-emission and other low—emission vehicles in the state by 2003.Car manufacturers hope the legislation will be rewritten to allow for more low--emission，rather than zero—emission，vehicles.
1. What have the Ford motor company.General Motor’s and Honda done concerning electric cars?
A)They have started to produce electric cars.
B)They have done extensive research on electric Cars
C)They have given up producing electric cars.
D)They have produced thousands of electric Cars
2. According to Tim Holmes of Ford Europe，battery-powered cars
A)will be the main transportation vehicles in the future
B)will not be the main transportation vehicles in the future.
C)will be good to the environment in the future
D)will replace petrol—powered vehicles in the future.
3. Which auto manufacturers are still producing electric vehicles?
A)Toyota and Nissan
B)General Motor’s and Honda
C)Ford and Toyota
D)Honda and Toyota
4. According to the eighth paragraph，hybrid cars
A)offer fewer mileage than petrol driven cars
B)run faster than petrol driven cars
C)run more miles than petrol driven cars
D)offer more batteries than petrol driven cars
5. Which of the following is true about the hope of car manufacturers according to the last paragraph?
A)Low-emission cars should be banned.
B)Only zero-emission cars are allowed to run on motorways.
C)The legislation will encourage car makers to produce more electric cars.
D)The legislation will allow more 10w.emission to be produced.
第3篇 New U.S.Plan for Disease Prevention
Urging Americans to take responsibility for their health,‘Health and Human Services Secretary Tommy Thompson on Tuesday launched a$15 million program to try to encourage communities to do more to prevent chronic diseases like heart disease，cancer and diabetes.
The initiative highlights the cost of chronic diseases一the leading causes of death in the United States——and outlines ways that people Can prevent them，including better diet and increased exercise.
“In the United States today,7 of 10 deaths and the vast majority of serious illness，disability and health care costs are caused by chronic diseases,"the Health and Human Services Department said in a statement.
The causes are often behavioral——smoking，poor eating habits and a lack of exercise.
“I am convinced that preventing disease by promoting better health is a smart policy choice for our future，”Thompson told a conference held to launch the initiatiative.
“Our current health care system is not structured to deal with the escalating costs
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 interested in starting new friendships: __1__. A lot of people's whole lives would change if they did just that.
You may have noticed that average person does not give his undivided attention to someone he as just met.__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 won 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 at that way."
__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 honest" 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.
__4__. 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. __5__ that is at least as important as how much we know.
A. In reply, Dr. Zunin would claim that a little practice can help us feel comfortable about changing our social habits.
B. Much of what has been said about strangers also applies to relationships with family members and friends.
C. In his opinion, success in life depends mainly on how we get along with other people.
D. Every time you meet someone in a social situation, give him your undivided attention for four minutes.
E. He keeps looking over the other person's shoulder, as if hoping to find someone more interesting in another part of the room.
F. He is eager to make friends with everyone.
1. D. 分析：空格前后句中出现了代词的呼应-- this advice--- that， 结合空格后句意(如果他们那样做的话，很多人的整个生活都会发生改变)判断that指代的内容是前句中提到的“这条建议”，所以判断空格处出现表意为“建议”的句子可能性最大，结合被选项的内容和用词判断D是答案。
3 A。分析：空格后句中出现了代词We，而被选项中只有A和C中有代词与We呼应。但A中还有changing our social habits与空格后句中的 become accustomed to any changes在语意上呼应，所以答案是A。
4. B。分析：前文中出现了“关于如何‘对待陌生人’的描述”，而且在下文中提到了“家庭成员(husband and wife or a parent and child)”，因此判断B是答案。
5 C。 分析：后句中的代词we在C中才有呼应的代词，而且在文章最后出现观点句是通常论述文的发展特点，因此判断C正确。
One Good Reason to Let Smallpox Live
It’s now a fair bet that we will never see the total extinction of the smallpox virus.The idea was to cap the glorious achievement of 1 980，when smallpox was eradicated in the wild，by destroying the killer virus in the last two labs that are supposed to have it -- one in the US and one in Russia?If smallpox had truly gone from the planet，what point Was there in keeping these reserves?
__1__reality，of course，it was naive to __2 __ that everyone would let __3__ of
such a potent potential weapon.‘Undoubtedly several nations still have__4__ vials. __5__ the last“official”stocks of live virus bred mistrust of the US and Russia,__6__ no obvious gain.
Now American researchers have __7__ an animal model of the human disease,
opening the __8__for tests on new treatments and vaccines.So once again there’s a good reason to__9__ the virus--just in __10__ the disease puts in a reappearance.
How do we __11__ with the mistrust of the US and Russia? __12__.Keep the
virus __13__ international auspices in a well-guarded UN laboratory that’s open to all countries.The US will object，of course，just as it rejects a multilateral approach to just about everything.But it doesn’t __14__the idea is wrong.If the virus __15__ useful，then let’s make it the servant of all humanity——not just a part of it.
1. A) In B) On C) At D)For
2. A)know B) imagine C) realize D)be aware
3. A)to go B) going C) go D) went
4. A) much B) more C) most D) a few
5. A)And B) While C) Whereas D) Although
6. A)since B) for C) because D) of
7. A)looked for B) sought
C) found D) talked about
8. A)method B) road C) street D) way
9. A)keep B) put C) destroy D) eradicate
10.A)need B) case C) necessity D) time
11.A)handle B) tackle C)deal D) treat
12.A) Difficult B) Hard C) Safe D) Simple
13.A) under B) in C) on D) for
14.A)say B) mean C) state D) declare
15.A) will be B) would be C) is D) are
1. A。分析：被选项是介词，注意搭配结构。in reality“实际上，事实上”是固定搭配使用的说法。
2. B。 分析：借助被选项的特点： know = be aware，排除A和D，再借助搭配结构(..是天真的)判断B(想象)是答案。
3. C。 分析：1et跟原形动词，go符合这一原则。
8.D.分析：借助被选项的特点：method 的习惯搭配介词是of，因此排除A; B和C都是具体指代“街道”，而 way可以抽象和具体的指代“道路”，判断D合适。Open the way v.为...创造条件; Clear the way v.扫清道路, 让路;On the way to在...途中;Find one’s way out 找到某人出去的路;寻找解决方法
10.B.分析：借助搭配结构“in..判断A，B和D是答案”，再根据空格后是一个句子的特点判断B(in case conj.万一)是答案。
11. C. 分析：借助搭配“.. with”直接判断C是答案。
Tackle vt 应付(难事等), 处理, 解决
13. A。 分析：被选项是介词，所以注意搭配结构：keep...in a .. laboratory; .. international auspices(赞助)，根据介词的基本含义和用法判断A(under prep.在...之下, 在...领导下)是答案。
14. B。 分析：因为空格是作谓语，而句子主语是“非人”，所以A，C 和D都不行(这些词的主语往往都是是“人”)。
15. C。分析：首先借助后面主句中的代词it判断前面的the virus应该是单数，而且状语从句结构中只能用一般时态来表示将来，所以判断C是答案。.