Today, the world wide web can be used both to retrieve information and to make it 51 to others. Information 52 on webpages in viewed by 53 of browser. The sources of in- formation linked in this way can be located on any computer 54 is also part of the web. Each information source 55 to an in­definite number of other webpages. Hypertext and hyperlinks allow users acting as receivers of information to wander form one source of information to another, 56 for themselves which information they wish to 57 to their browser and which links they want to 58 .
　　The addresses of webpages can be found by using the many hundreds of general and specialized search engines which provide 59 to databases which hold information on them. Once a webpage has been found, hyperlinks may point 60 other places of interest on the web. Addresses of webpages also 61 in other more conventional media such as maga­zines, newspapers and television programs, and on posters. WebPages, in their turn, facilitate access to information made available by other 62 of media, for example, collections held in libraries or programs broadcast on television.
　　Most webpages offer interactive opportunities which go beyond moral allowing visitors freedom as to when and how they visit a page and where they might choose to go next. Feedback can be kept formal via a questionnaire which can be filled 63 , or informal by providing an address for e-mail or even by 64 a digital quest book for comments left for other users to read. Although all webpages are protected so that unauthorized visitors cannot make unsolicited changes to them, it is also possible to 65 access to pages on the Internet to those holding a password.
51. A. available B. obtainable C. achievable D. amicable
52. A. displayed B. displaying C. displayable D. is displayed
53. A. medium B. vehicle C. agent D. means
54. A. what B. that C. that D. it
55. A. maybe linked B. may be linked C. may is linked D may linked
56. A. deciding B. decided C. decide D. to decided
57. A. transition B. transmit C. transform D. transfer
58. A. flip B. slip C. skip D. skim
59. A. success B. access C. assess D. possess
60. A. about B. on C. to D. at
61. A. to appear B. appeared C. appearing D. appear
62. A. modes B. forums C. shapes D. forms
63. A. up B. out C. with D. over
64. A. install B. installed C. installing D. installs
65. A. constrain B. confine C. restrain D. limit

参考答案
51. A   52. A   53. D   54. B   55. B   56. A   57. D   58. C   59. B   60. C 61.D    62. D   63. B   64.C    65. D