There is evidence that the usual variety of high blood pressure is, in part, a familial disease. Since families have similar genes as well as similar environments, familial diseases could be due to shared genetic influences, to shared environmental factors, or to both. For some years, the role of one environmental factor commonly shared by families, namely dietary salt (i.e. sodium chloride), has been studies at Brook Haven National Laboratory. These studies suggest that frequent excess salt eating can lead to high blood pressure in man and animals. Some individuals, however, and some rats consume large amounts of salt without developing high blood pressure. No matter how strictly all environmental factors were controlled in these experiments, some salt-fed animals never developed high blood pressure whereas a few rapidly developed very serious high blood pressure followed by early death. These marked variations were interpreted to result from differences in genetic constitution. By mating in successive generations only those animals that failed to develop high blood pressure from salt eating, a resistant strain (the “R“ strain) has been evolved in which consumption of large quantities of salt falls to influence the blood pressure significantly, in contrast, by mating only animals that quickly develop high blood pressure from salt, a sensitive strain (“S“ strain) has also been developed. The availability of these two strains permits investigations not possible formerly. They provide a likely laboratory model on which to investigate some clinical(临床的) aspects of the human types of high blood pressure. More important, there might be the possibility of developing methods by which genetic likelihood of human beings to develop high blood pressure can be defined without waiting for its appearance. Radioactive(放射性的) sodium 22 was an important “tool“ in working out the characteristics of the sodium chloride metabolism.The study of the effects of salt on high blood pressure was carried out ______. because members of the same family tend to used similar amounts of salt to explore the long-term use of a sodium-based substance because it was proven that salt caused high blood pressure because of the availability of chemically pure salt

This country, as Lincoln said, belongs to the people. So do the natural resources which make it rich. They supply the basis of our prosperity now and hereafter. In preserving them, which is a national duty, we must not forget that monopoly is based on the control of natural resources and natural advantages, and that it will help the people little to conserve our natural wealth unless the benefits which it can yield are given back to the people. Let us remember, also, that conservation does not stop with the natural resources. The principle of making the best use of all we have requires that we stop the waste of human life in industry and prevent the waste of human welfare which flows from the unfair use of concentrated power and wealth in the hands of men whose eagerness for profit blinds them to the cost of what they do. We have no higher duty than to promote the efficiency of the individual. There is no surer road to the efficiency of the nation.

Community cancer clusters are viewed quite differently by citizen activists than by epidemiologists. Environmentalists and concerned local residents, for instance, might immediately suspect environmental radiation as the culprit when a high incidence of cancer cases occurs near a nuclear facility. Epidemiologists, in contrast, would be more likely to say that the incidences were “inconclusive“ or the result of pure chance. And when a breast cancer survivor, Lorraine Pace, mapped 20 breast cancer cases occurring in her West Islip, Long Island, community, her rudimentary research efforts were guided more by hope that a specific environmental agent could be correlated with the cancers than by scientific method. When epidemiologists study clusters of cancer cases and other noncontagious conditions such as birth defects or miscarriage, they take several variables into account, such as background rate (the number of people affected in the general population), cluster size, and specificity (any notable characteristics of the individual affected in each case). If a cluster is both large and specific, it is easier for epidemiologists to assign blame. Not only must each variable be considered on its own, but it must also be combined with others. Lung cancer is very common in the general population. Yet when a huge number of cases turned up among World War II shipbuilders who had all worked with asbestos, the size of the cluster and the fact that the men had had similar occupational asbestos exposures enabled epidemiologists to assign blame to the fibrous mineral. Although several known carcinogens have been discovered through these kinds of occupational or medical clusters, only one community cancer cluster has ever been traced to an environmental cause. Health officials often discount a community’s suspicion of a common environmental cause because citizens tend to include cases that were diagnosed before the afflicted individuals moved into the neighborhood. Add to this the problem of cancer’s latency. Unlike an infectious disease such as cholera, which is caused by a recent exposure to food or water contaminated with the cholera bacterium, cancer may have its roots in an exposure that occurred 10 to 20 years earlier. Do all these caveats mean that the hard work of Lorraine Pace and other community activists is for nothing? Not necessarily. Together with many other reports of breast cancer clusters on Long Island, the West Islip situation highlighted by Pace has helped epidemiologists lay the groundwork for a well designed scientific study.The “hope“ mentioned in Paragraph 1 refers specifically to Pace’s desire to______. help reduce the incidence of breast cancer in future generations improve her chances of surviving breast cancer determine the cause responsible for her own breast cancer case identify a particular cause for the breast cancer cases in West Islip

Experts predict that China’s healthcare market will have an annual growth of 6 to 8 percent in the next few years, making it one of the potentially most prosperous. In Shanghai, annual medical expenditure is estimated to be 16 billion yuan (U. S. 93 billion). With an increasingly【31】population, the growing consumption power and longer life【32】of local residents, the medical market has great opportunities. However l limited medical resources cannot meet people’s needs【33】financial deficits in State-owned hospitals.【34】, there is room for a range of different medical organizations. As is the case with many State-owned enterprises, public hospitals in the past half century have learned a lot of bad habits:【35】management, over-staffing and bureaucratic operating procedures. Being a member of World Trade Organization (WTO), China has to【36】its promise to open the health industry to foreign capital in coming years. By then, public hospitals will be facing fierce competition from Western giants they have never prepared for. So it’s quite urgent【37】them to learn how to operate as an enterprise and how to survive in the competitive market economy of the future. As a【38】, the healthcare sector was first opened to domestic private investors. Since the first private hospital opened in 1999, private investors from Shenzhen, Sichuan and Zhejiang provinces have been scrambling to enter Shanghai.【39】show that about 20 private hospitals have been set up in the city, although this number,【40】with more than 500 public hospitals, is still quite low.

School secretary: Good morning. Can I help you? Student: Yes, I’d like to enroll for the course. School secretary: ______ Thank you very much. Nice to see you here. Certainly. What’s your name please? Sorry. Can I see your passport please?

House agent: Good morning. Sunshine Real Estate. Chris Lee speaking. Woman:______ Is it still available? Excuse me, do you have a two-bedroom apartment for rent? Hello. I’m calling about the two-bedroom apartment advertised in today’s Daily News. Hello. Is the two-bedroom apartment advertised in today’s Daily News still available? Excuse me. I have some questions about the two-bedroom apartment advertised in today’s Daily News.

Nurse: Do you have any designated doctor?Patient: Yes, Dr. Hurt, Cliff Hurt.Nurse: Here is your registration card. Dr. Hurt is at clinic No. ______. You may stay here and wait for your right You can sit over there and wait for your turn You may stand in line here and wait for your arrangement You may sit here and wait for your order

Customer: Excuse me, sir. Clerk: ______. Customer: I’d like to cash a check. Would you please tell me which window should I go to? Clerk: You can cash checks over there at window 6. What? Can I help you? Yes, may I help you? It’s all right. It doesn’t matter.

A: How’s everything going? B: ______ Everything is finished. Everything has been done. Not so had, you know. Not doing wrong, you know.

She got a ______ job while she was waiting to go to the university. steady attractive temporary permanent

It’s ______ of her to refuse to admit that she is wrong; she is very stubborn. characteristic peculiar specific particular

I doubt that any historically valid treatment of that presidential administration can emerge for at least another decade, if then. I confess that when I came out of the White House I signed up to do an “insider volume“, but sober, professional second thoughts have led me to put that project on ice until at least 1980. The problem is that I simultaneously know too much, and not enough. I know what I thought was happening. But I cannot fully document what happened. And I have seen enough highly classified documents to know that most of what the observers thought was happening was at best haft right, at worst dead wrong. This has steered me in a different direction as far as writing is concerned. I am now preparing what is frankly and unashamedly an ex parte memoir, “My Experiences in Washington.“ It is based on what I believed to be true, on the picture as I conceptualized it, of the presidential administration under which I worked.

Woman: I think the Internet is more of a distraction than a benefit to students. Man: That’s true. ______ Chatting on the net can be very expensive. They are putting less time in schoolwork now. The web pages can sometimes help them with schoolwork. Their schoolwork doesn’t take long enough, does it?

Guest: Oh, it’s ten o’clock, I’d better go now. Host:______. OK. Please walk slowly. Why do you want to go now? Don’t you want to stay? Won’t you stay for another cup of coffee? Yeah, it’s really late. Why not immediately?

Caller. Hello! I want to make a person-to-person call to Toronto, Canada. The number is 932-0806.Operator: ______ But I don’t know whom do you want to call. What’s the name of the party you’re calling? What’s the address of the person you’re calling? What’s the extension number you’re calling?

It can be implied that the main difference between “S“ and “R“ strains is in their ______.

It is implied in the second paragraph that ______.

Among the results of the research discussed in this passage, the most beneficial might be ______.

We can infer from the passage that ______.