TOEFL单词短语学习：

numerous adj. 许多的，很多的 (adjective): many
- There were numerous articles in the paper on that problem.

preface vt. 为…加序言；以…开始 (verb): to introduce or begin
The manager prefaced his presentation with the minutes from last meeting.

prospect n. 前途；预期；景色 (noun): the anticipation that something might happen
- His prospects aren't very good for getting a job because he lacks the needed skills.

traumatic adj. 外伤的；创伤的 (adjective): very upsetting or difficult
- Because of air pollution, we have seen some very traumatic changes in the environment..

limb n. 肢，臂；分支；枝干 (noun): a part of the body, like an arm or leg
- Many artificial limbs have been prepared for .

severed adj. 切断的；隔断的 (off) (verb): cut off completely
- The two businesses severed off negotiations after they couldn't agree on any of the important issues.

lexicon n. 词典，辞典 (noun): vocabulary
- Expanding your lexicon in this technical field will help you a great deal.

to be elated 心花怒放 (verb): very happy or excited
- They were elated to hear the good news.

discard vt. 抛弃；放弃；丢弃 (verb): to throw away, to dispose of
- The fish in this river are dying because local industries have been reckless in discarding their waste materials.