導讀：詞組能有效的幫助大家提高完型和句子的理解與寫作質(zhì)量，為保證大家能夠靈活運用考研重點詞組，社科賽斯李梅老師特配以相應(yīng)的例句，幫助大家更快地獲得更高的分數(shù)。
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81. back and forth 來回地，反復(fù)地
Move back and forth like a ship.
像船一樣來回地移動。
82. balance between ...之間的平衡
At times like that you have to strike a balance between sleep and homework.
在這種情況下，你得在休息和做作業(yè)之間找到一種平衡。
83. barrier to ...的障礙
The greatest barrier to success is the fear of failure.
成功最大的障礙就是對失敗的恐懼。
84. be based on 以...為基礎(chǔ)
Scientific theories must be based on facts.
科學理論必須以事實為根據(jù)。
85. bear／keep in mind記住
You must bear in mind that your parents expect you to become a good doctor.
你要記住你的父母希望你成為一名好醫(yī)生。
