完形填空（共20小题；每小题1分，满分20分）
阅读下面短文，掌握其大意，然后从36—55各题所给的四个选项（A、B、C、D）中，选出最佳选项，并在答题卡上将该项涂黑。
Shopping habits in the United States have changed greatly in the last quarter of the 20th century. _36  in the 1900s most American towns and cities had a Main Street. Main Street was always in the heart of a town. This street was 37 on both sides with many _38 businesses. Here, shoppers walked into stores to look at all sorts of merchandise: clothing, furniture, hardware, groceries. _39 , some shops offered _40 .These shops included drugstores, restaurants, shoe-repair stores, and barber or hairdressing shops. _41 in the 1950s, a change began to _42 . Too many automobiles had crowded into Main Street _43_ too few parking places were _44_ shoppers. Because the streets were crowded, merchants began to look with interest at the open sp aces _45_ the city limits. Open space is what their car-driving customers needed.
And open space is what they got _46 the first shopping centre was built. Shopping centers, or rather malls,  47_ as a collection of small new stores _48_ crowded city centers. _49_ by hundreds of free parking space, customers were drawn away from _50_ areas to outlying malls. And the growing _51_ of shopping centers led _52_ to the building of bigger and better stocked stores. _53_ the late 1970s, many shopping malls had almost developed into small cities themselves. In addition to providing the _54_ of one stop shopping, malls were transformed into landscaped parks,  55_ benches, fountains, and outdoor entertainment.  
36. A. As early as     B. Early    C. Early as        D. Earlier
37. A. built        B. designed      C. intended      D. lined
38. A. varied    B. various         C. sorted D. mixed up
39. A. Apart from     B. However      C. In addition   D. As well
40. A. medical care B. food     C. cosmetics    D. services
41. A. Suddenly         B. Abruptly       C. Contrarily    D. But
42. A. be taking place      B. take place     C. be taken place      D. have taken place
43. A. while      B. yet        C. though          D. and then
44. A. available for  B. available to C. used by         D. ready for
45. A. over        B. from     C. out of   D. outside
46. A. when      B. while    C. since    D. then
47. A. started  B. founded        C. set up   D. organized
48. A. out of     B. away from   C. next to          D. near
49. A. Attracted       B. Surprised     C. Delighted     D. Enjoyed
50. A. inner      B. central          C. shopping      D. downtown
51. A. distinction      B. fame    C. popularity    D. liking
52. A. on  B. in turn C. by turns        D. further
53. A. By  B. During C. In D. Towards
54. A. cheapness     B. readiness     C. convenience         D. handiness
55.A. because of                B. and                     C. with                       D. provided