2. 虚拟语气 We hurried back to school lest/ for fear that it (should) rain. 我们匆匆忙忙地赶回学校，生怕天会下雨。

　　3. 比较级the more…the more The more time a person spends on his work， the less time he has to play. 一个人花在工作上的时间越多，花在玩耍上的时间就越少。

　　4. This subject is far more difficult than everybody has previously expected. 这门课程比每个人以前预料的还要难得多。

　　5. more than…/rather than… A political figure's success depends more on external factors than his own characteristics. 一个政治人物的成功与其取决于他个人的特点，不如说取决于外部因素。

　　6. 让步状语 Whether you believe him or not， you have to make the decision. 无论你是否相信他，你都必须做出决定。

　　7. no matter what/ who/when/how…， No matter how hard he tried， he couldn't persuade his friends to give up the adventure. 无论他怎么努力，都不能说服他的朋友们放弃冒险。

　　8. despite/in spite of …， He decided to carry out the plan in spite of the protest from his parents. 他决定不顾父母的反对执行他的计划。

　　9. 结果状语 I broke my glasses so that I couldn't see clearly what happened. 我打破了眼镜，以至于看不清当时发生了什么事。

　　10. The density of the star has become so great that it may explode at some time. 这颗恒星的密度如此之大，以至于它会在某一时刻爆炸。

　　11. 非限定性定语从句 As we expected正如我们所预料的那样/ As is well known众所周知， the project was finished successfully on time. 项目成功地提前完成。

　　12. 形式主语 It's no doubt that correct decisions made today will have a good effect on future. 毫无疑问，今天做出的正确决策将对未来有很好的影响。

　　13. 形式宾语 Many people find it important to keep a good living habit. 很多人认为保持一个良好的生活习惯非常重要。

　　14. 宾语补足语 The new electronic techniques make possible the effect that has never been created before. 新的电子技术使得一种从未有过的音响效果成为可能。

　　15. 倒装句 Not until recently did we realize that language was closely related to culture. 直到最近我们才意识到语言与文化密切相关。

　　16. Under no circumstances should you hesitate to offer your opinion as it is. 在任何情况下你都应毫不犹豫地说出你真实的想法。

　　17. 比较状语such … as … Such people as you described can hardly succeed in nowadays. 像你描述的那种人在当今社会很难取得成功。

　　18. 原因状语be different/ similar … in that…Robots are different from automatic machines in that they can be reprogrammed to do another job. 机器人和自动化机器的不同之处在于它能被重新编程完成其它的任务。

　　19. 宾语从句people hold different attitudes as to… 人们对于是否应该用动物做实验持不同的态度。people hold different attitudes as to whether animals should be used in experiments.

　　20. 并列句 …not only…but also… Sports can not only benefit our body， but also contribute immensely to mental health. 运动不仅对我们的身体有益，而且还极大地有助于精神健康。