第6部分：完形填空(第51～65题，每题1分，共15分)
下面的短文有15处空白，请根据短文内容为每处空白确定1个最佳选项。
51. A. therefore
B. thus
C. for example
D. nevertheless
52. A. simpler
B. more complex
C. more meaningless
D. more troublesome
53. A. starting
B. stopping
C. ending
D. discontinuing
54. A. analyzed
B. examined
C. explored
D. developed
55. A. before
B. after
C. under
D. above
56. A. one
B. ones
C. other
D. others
57. A. social
B. technical
C. personal
D. historical
58. A. if
B. as if
C. though
D. as though
59. A. that
B. which
C. what
D. whatever
60. A. size
B. shape
C. appearance
D. effectiveness
61. A. excludes
B. contains
C. looks like
D. tastes of
62. A. desired
B. side
C. little
D. immediate
63. A. for
B. with
C. to
D. into
64. A. because of
B. before
C. because
D. and
65. A. weak
B. strong
C. elder
D. pregnant