e.g. Since much of the variation is due to genes, one more agent of evolution has gone.
因為大部分差異是由基因引起的，所以又一個進化的因素消失了。
2. n. (演員、作家等)經(jīng)紀人
e.g. My agent has a new script for me to look at.
我的經(jīng)紀人有一個新劇本給我看。
3. n. 間諜，特工
e.g. Residents say they understand that agents have an important job, but they accuse the feds of lies, intimidation and harassment.
居民們說，他們理解特工的重要工作，但他們指責聯(lián)邦調(diào)查局的謊言、恐嚇和騷擾。
4. n. (化學(xué))劑
e.g. The use of a topical agent to eradicate bacteria from wounds is potentially cheaper and may well improve antibiotic therapy in the future.
使用局部藥劑來消除傷口上的細菌可能要便宜一些，也可能大大改善未來抗生素療法。
nature
常用：n. 自然界，大自然
生義：n. 天性，本性；自然力/規(guī)律；基本特征；種類
1. n. 天性，本性
e.g. The jury agreed that the nature of the game, not the helmet, was the reason for the athlete’s injury.
陪審團認為，造成該運動受傷的是這項運動本身的險性，而不是頭盔。
2. n. 自然力/規(guī)律
e.g. Just let nature take its course.
就順其自然吧。
3. n. 基本特征
e.g. They asked a lot of questions about the nature of our democracy.
他們提出了很多關(guān)于我們民主基本特征的問題。
4. n. 種類
e.g. The support being given is of a practical nature.
正在提供的這種支持是實質(zhì)性的。
doctor
常用：n. 醫(yī)生；博士
生義：v. 篡改；（在飲料或食物中）摻入有毒物質(zhì)；（給動物）絕育；給… 療傷
1. v. 篡改，偽造
e.g. Like other human beings, he encounters moral issues even in the everyday performance of his routine duties—he is not supposed to cook his experiments, manufacture evidence, or doctor his reports.