1. There is no essential difference between the two drafts.
    两份草稿没有本质上的不同。

2. Hard work is essential to success.
    成功必须努力工作。

3. Food is essential to life.
    食物是维持生命不可或缺的。

1. The book deals with the essentials of English grammar.
    这本书论述英语语法的要点。

2. Our course deals with the essentials of management.
    我们的课程讲述管理的基本要点。

1. 必要的：对每个高中毕业生来说,准备高考是十分必要的(essential) 除非薪水太低,上班太远,否则他就会接受这份工作的(unless)

2. 世纪典藏：肯尼吉的<世纪典藏>>(Essential)精选辑,首周进榜就分别攻下五大唱片和g-music西洋榜的三、五名;曾与他合作的王力宏,则以<盖世英雄>>包办双榜冠军. 两人今晚将在香港再携手,王力宏出任Kenny G的演奏会嘉宾,演唱三首歌.

1. 绝对必要的;必不可少的;基本的
    Something that is essential is extremely important or absolutely necessary to a particular subject, situation, or activity.

    e.g. It was absolutely essential to separate crops from the areas that animals used as pasture...
           将庄稼和放牧区分开绝对必要。
    e.g. As they must also sprint over short distances, speed is essential...
           由于他们也必须进行短跑，因此速度至关重要。

2. 必需品;不可或缺之物
    The essentials are the things that are absolutely necessary for the situation you are in or for the task you are doing.

    e.g. The flat contained the basic essentials for bachelor life.
           那套公寓配有单身生活的基本必需品。

3. 基本的;本质的；根本的
    The essential aspects of something are its most basic or important aspects.

    e.g. Most authorities agree that play is an essential part of a child''s development...
           大多数权威人士都同意，玩耍在孩子成长过程中起着非常重要的作用。
    e.g. In this trial two essential elements must be proven: motive and opportunity.
           在这次审讯中，必须证明两个基本因素：动机和时机。

4. （某学科的）基础，基本知识
    The essentials are the most important principles, ideas, or facts of a particular subject.

essential

    e.g. ...the essentials of everyday life, such as eating and exercise...
           饮食、锻炼等日常生活的要素
    e.g. This has stripped the contest down to its essentials.
           这就使比赛精简到最基本的环节。

1. anything indispensable

    e.g. food and shelter are necessities of life
           the essentials of the good life
           allow farmers to buy their requirements under favorable conditions
           a place where the requisites of water fuel and fodder can be obtained

    Synonym: necessityrequirementrequisitenecessary

1. defining rights and duties as opposed to giving the rules by which rights and duties are established

    e.g. substantive law

    Synonym: substantive

2. basic and fundamental

    e.g. the essential feature

3. of the greatest importance

    e.g. the all-important subject of disarmament
           crucial information
           in chess cool nerves are of the essence

    Synonym: all-important(a)all important(p)crucialof the essence(p)

4. absolutely necessary
    vitally necessary

    e.g. essential tools and materials
           funds essential to the completion of the project
           an indispensable worker

    Synonym: indispensable

5. being or relating to or containing the essence of a plant etc

    e.g. essential oil