61.on the average (=on average, on an average)平均
62.(be) aware of (=be conscious of, havingknowledge 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