21.at present 目前，眼下

　　At present, I don't want to go aboard. 眼下我不想出国。

　　He is at present serving his life sentence. 他眼下在服终生监禁。

　　22.attribute to 把……归因于

　　He attributed his success to good luck. 他把成功归因于运气。

　　Air pollution has been partly attributed to cars. 空气污染部分原因是由于汽车的使用。

　　23. aware of 明白，意识到

　　I am not aware of his intentions. 我不明白他的意图。

　　I was not aware of my danger. 我没意识到危险。

　　24.base on/upon 以……为基础，基于

　　The novel is based on the historical facts. 这部小说是根据历史题材写成的。

　　The belief is based upon practical experience. 这信仰来源于实践经验。

　　25.be able to 能，会

　　Since his accident, he hasn't been able to leave the house. 他自从出了事故以来就没能离开这房子。

　　The frog is able to jump 3 meters at one time.这只青蛙一次能跳三米远。

　　26.be absorbed in 全神贯注于，专心于

　　She was absorbed in the book. 他全神贯注地读书。

　　He was so absorbed in his work that he rarely noticed what happened around him.他全神贯注地工作，很少注意到周围发生了什么。

　　27.be composed of 由……组成

　　The class was evenly composed of boys and girls. 这班级由男生与女生平均组成。

　　What is water composed of? 水是由什么组成的?

　　28.be concerned with 关于，与……有关

　　This book is concerned with computer technology. 这本书是关于计算机技术的。

　　He is always concerned with state affairs. 他总是关心国家大事。

　　29. be fit for 适合

　　The book is fit for children.这本书适合孩子。

　　The houses are now fit for human habitation. 这些房子适合人类居住。

　　30.be/go on a diet 节食

　　I mustn't have chocolate. I am on a diet. 我不能吃巧克力，我在节食。

　　Going on a diet is not the best way to reduce weight. 节食不是减肥的最佳办法。

　　31.be related to 与……有关，涉及

　　This article is related to the international situation. 这篇文章讲的是国际形势。

　　Painting is related to art. 绘画与艺术有关。

　　32.be/get tired of 对……感到厌倦

　　I am tired of exams. 我厌倦了考试。

　　I am tired of eating the same food every day. 我厌烦了每天吃同样的食物。

　　33. be/get used to 习惯于

　　We are used to the cold weather here. 我们适应了这里的寒冷天气。

　　34.bear/keep…in mind 牢记在心

　　Bear in mind what I am saying. 记住我说的。

　　Please bear in mind the instructions the doctor has given you. 记住医生给你的指示。

　　35.because of 因为

　　Because of his laziness, he failed the exam again. 因为懒惰，他考试再次不及格。

　　Because of his bad leg, he could not walk as fast as others. 由于他的残腿，他不能与别人走一样的快。

　　36.begin/start with 以……开始

　　The first word of a sentence should begin with a capital letter.句子的首字母应大写。

　　Knowledge begins with practice. 理论来源于实践。

　　37.before long 不久，很快

　　The storm will be over before long. 风暴很快就会过去。

　　The book will be published before long. 这本书不久之后就出版。

　　38.believe in 信任，相信

　　I don't believe in ghosts. 我不信鬼。

　　Marxism believes in the primacy of matter. 马克思主义相信物质第一性。

　　39.belong to 属于

　　The land belongs to a big family. 这片土地属于一个大家庭。

　　The future belongs to a big family. 未来属于年轻的一代。

　　40.benefit from 从……获益

　　I benefited a lot from his advice. 我从他的建议中受益非浅。

　　He will benefit from the new way of doing business. 他会从新的生意之道中获益匪浅。