单词记忆不能只记中文释义，要掌握其常见用法、固定搭配，并且在能力范围内利用词根触类旁通。考博英语对于词汇的考查主要体现在考生“同义替换”的能力上，也就是考查考生对于语言多样性的把握，所以考生在背单词的时候一定要掌握单词的同义词。而完型填空要求考生对词义的把握也更为强，大家要好好的复习。
retreat
n / v. 撤退，退却
【例】All the villagers kept themselves in readiness to retreat as soon as the enemy came.所有的村民都时刻准备着等敌人一来就撤退。
【同义替换】retire, withdraw
【例题】It was inevitable that this primacy should have narrowed as other countries grew richer. Just as inevitably, the retreat from predominance proved painful.
随着其他国家日益强盛，美国的这一优势地位逐渐下降是不可避免的。从优势地位上退出的痛苦也同样是不可避免的。
rough
a. 粗糙的;粗略的，大致的;粗野的，粗暴的
【例】Although these figures are only rough estimates, they do strikingly underline the seriousness of the problem.虽然这些数字是比较粗略的估计，但在很大程度上表面了这个问题的严重性。
【同义替换】unsmooth; approximate
【派生】roughly ad.粗略地，大约;粗暴地，粗糙地，粗鲁地
approximately ad.近似地，大约
【例题】What they found, in attempting to model thought, is that the human brain’s roughly one hundred billion nerve cells are much more talented-and human perception far more complicated-than preciously imagined.
在试图建造思维模型的过程中，研究人员发现，人类大脑中的近1000亿个神经细胞要比以前想象的更聪明，人类的感觉器官也比以前想象的更复杂。
paradox
n. 似是而非的话，自相矛盾的话，反论
【例】The share of information and the security of information are the most paradox in computer network.计算机网络的信息共享与信息安全是网络上最大的悖论。
【构词】para-(前缀=contrary 相反)+dox(=opinion 观点)→自相矛盾的观点
【同义替换】inconsistency, contradiction
【派生】paradoxical a.矛盾的 paradoxically ad.矛盾地
【例题】His argument is that the unusual history of these people has subjected them to unique evolutionary pressures that have resulted in this paradoxical state of affairs.
他的观点是，这些人非同寻常的经历使他们遭受了其他人所没有经受过的进化压力，而这些压力最终导致了这种矛盾的状况。