Cloze 3

    Among the devastating consequences of AIDS has 1 its epidemic spread in the developing world. The disease has caused 2 suffering, debilitation, loss of life and disruption of family, social and economic 3. Because of the considerable expense and logistical difficulty in providing antiviral drugs to populations 4 with the human immunodeficiency virus 5 the world, the biomedical community is looking towards vaccines to help solve this compelling problem.

    The search for an AIDS vaccine began more than 15 years ago with great 6 and high expectations. With the 7 of the human immunodeficiency virus (HIV) as the cause of AIDS, it seemed that a 8 would follow closely behind. But despite a large concerted effort, the problem has proven more difficult than 9, and progress has not 10 the 11 hopes. Here I review the 12 scientific obstacles confronting the development of an effective HIV vaccine, and I consider 13 strategies to overcome these obstacles.

    It is instructive to consider the circumstances that have 14 to past successes in vaccine development. The smallpox vaccine is 15 the most successful inventions in the history of 16. Why, 200 years ago, without the benefit of modern biotechnology, did the smallpox vaccine succeed so readily while an AIDS vaccine 17 elusive? The answer lies in an experiment of nature that provided, to an astute observer, a clear direction for smallpox vaccine development. In this classic story of 18 discovery, Edward Jennet noticed that milk maids who had previously contracted cowpox were 19 to smallpox infection. This observation was the critical event leading to the finding that the cowpox virus cross-reacted immunologically with the smallpox virus and could 20 be used to protect against smallpox.

1. A. on B. with C. been D. about

2. A. unpredicted B. uncontrollable C. unimaginable D. unprecedented

3. A. stability B. instability C. permanency D. soundness

4. A. harmed B. infected C. infectious D. infection

5. A. everywhere B. throughout C. devastating D. occupying

6. A. difficulty B. concern C. optimism D. pessimism

7. A. confirmation B. identification C. information D. precaution

8. A. cure B. capsule C. medication D. vaccine

9. A. ever B. anticipated C. possible D. necessary

10. A. surpassed B. outbalanced C. matched D. rivaled

11. A. origin B. initial C. great D. modest

12. A. majority B. primary C. principal D. premier

13. A. potential B. initiative C. practical D. existing

14. A. lead B. caused C. contributed D. cooperated

15. A. by far B. till now C. among D. considered

16. A. vaccine B. medicine C. smallpox D. AIDS

17. A. slowly B. fails C. remains D. counts

18. A. accidental B. importance C. scientific D. vaccine

19. A. vulnerable B. resistant C. opposing D. defendant

20. A. safely B. therefore C. as well D. possibly

Cloze 4

    It"s widely believed that we have already lived in the age of technology. It is sometimes1as all the material products of a culture, but it also includes the scientific knowledge that is2to material production. 

    In the early twentieth century, Thorstein Veblen stressed the role of 3 invention in bringing about social changes. He thought that a new invention4slowly lead to changes in social manner and attitudes. 5 each invention makes more inventions possible, the6of technological development tends to speed up. Benjamin Franklin experimented with7in the eighteenth century, but it was a hundred years8. Thomas Edison moved from theory and experiment to practical9. In the hundred years since Edison’s invention, the10of electricity has led to tens of thousands of inventions, 11engines, automobiles, airplanes and computers. What to do12this increasing number of invention and13to control the social changes they produce give14to some of the greatest demands15our time. 

    Industrialization-the process of moving from hand tools to power16- has led to a number of social changes. A17economy requires specialized factory workers and trained18to watch over them; therefore, the required level of education19to increase. The growth of a more educated middle class tends to20inequalities by distributing income more widely.

　　1.A. regarded B. considered C. defined D. classified

　　2.A. applied B. referred C. used D. put

　　3.A. technology B. technique

　　C. technological D. technical

　　4.A. should B. might C. would D. could

　　5.A. While B. Since C. Unless D. Because

　　6.A. proportion B. rate C. ratio D. percentage

　　7.A. energy B. electricity C. fuel D. oil

　　8.A. before B. that C. after D. since

　　9.A. application B. applications C. usage D. usages

　　10.A. discovery B. creation C. invention D. emergence

　　11.A. concluding B. involving C. including D. containing

　　12.A. with B. around C. about D. as

　　13.A. what B. how C. why D. when

　　14.A. way B. up C. rise D. off

　　15.A. for B. in C. of D. a t

　　16.A. machine B. tool C. machinery D. means

　　17.A. special B. specialized C. specific D. particular

　　18.A. officials B. boss C. leaders D. managers

　　19.A. attempts B. intends C. means D. tends

　　20.A. scatter B. attribute C. complain D. resolve

下一页继续