俗话说“条条大路通罗马”，背诵
21. after
22. against
23. among
24. at
25. before
26. between
27. by
28. down
29. from
30. in
31. off
32. on
33. over
34. through
35. to
36. under
37. up
38. with
39. as
40. for
41. of
42. till
43. than
44. a
45. the
46. all
47. any
48. every
49. no
50. other
51. some
52. such
53. that
54. this
55. i
56. he
57. you
58. who
59. and
60. because
61. but
62. or
63. if
64. though
65. while
66. how
67. when
68. where
69. why
70. again
71. ever
72. far
73. forward
74. here
75. near
76. now
77. out
78. still
79. then
80. there
81. together
82. well
83. almost
84. enough
85. even
86. little
87. much
88. not
89. only
90. quite
91. so
92. very
93. tomorrow
94. yesterday
95. north
96. south
97. east
98. west
99. please
100. yes