61. on the average (=on average, on an average) 平均
62. (be) aware of (=be conscious of , having knowledge or consciousness)意识到,知道.
63. at the back of (=behind) 在…后面
64. in the back of 在…后部(里面); on the back of 在…后部(外面); be on one’s back(=be ill in bed) 卧病不起.
65. at one’s back(=supporting or favoring sb.) 支持,维护; have sb. at one’s back 有…支持, 有…作后台
66. turn one’s back on sb. (=turn away from sb. in an impolite way) 不理睬(某人),背弃,抛弃
67. behind one’s back 背着某人(说坏话)
68. be based on / upon 基于
69. on the basis of 根据…, 在…基础上
70. beat…at 在…运动项目上打赢

71. begin with 以…开始. to begin with (=first of all) 首先, 第一(经常用于开始语)
72. on behalf of (=as the representative of) 以…名义
73. believe in(=have faith or trust in; consider sth./sb. to be true) 相信,依赖,信仰.
74. benefit (from) 受益,得到好处.
75. for the benefit of 为了…的利益(好处)
76. for the better 好转
77. get the better of (=defeat sb.) 打败, 胜过.
78. by birth 在出生上,论出身,按血统 at birth 在出生时; give birth to 出生
79. blame sb. for sth. 因…责备某人 . blame sth. on sb. 把…推在某人身上
80. in blossom开花(指树木) be in blossom开花(强调状态) come into blossom开花(强调动作)

81. on board 到船上, 在船上, 上火车或飞机
82. boast of (or about) 吹嘘
83. out of breath 喘不过气来
84. in brief(=in as few words as possible)简言之
85. in bulk 成批地,不散装的
86. take the floor 起立发言
87. on business 出差办事.
88. be busy with sth.于某事 。 be busy doing sth. 忙于做某事
89. last but one 倒数第二.
90. but for (=without) 要不是. 表示假设

91. buy sth. for…money 用多少钱买
92. be capable of 能够, 有能力 be capable of being +过去分词:是能够被…的
93. in any case(=for love or money, at any rate, at any price, at any cost, whatever happens; anyhow)无论如何
94. in case (=for fear that) 万一;
95. in case of (=in the event of)如果发生…万一 in the case of 至于…, 就…而言
96. in no case在任何情况下都不(放句首倒装句)
97. be cautious of 谨防
98. center one’s attention on(=focus one’s attention on) 把某人的注意力集中在…上
99. be certain of (=be sure of) 有把握, 一定.
100. for certain of (=for sure )肯定地,有把握地

这些很经典的，强烈推荐熟记于心！！！