essential/basic/central/chief/crucial/important/main.导航词义：主要的，重要的

1. essential:adj. 必要的，重要的，基本的.语气较强，强调极其重要、必不可少的，暗含某物如缺少某部分，则失去其本质特征的意味。

Water and food are essential to life.

水和食物对生命是必不可少的。

Her most essential quality is kindness.

她最重要的品质是善良。

2. basic:adj. 基本的，主要的.指构成事物最重要、最根本部分的。

the basic research/rule

基础研究/基本法规

He began to learn the basic principles of chemistry.

他开始学习基本化学原理。

The basic principles must be preserved.

这些基本原则必须保留。

3. central:adj. 重要的，主要的.强调相比较而言更重要或更有影响力的。

a central figure/idea/role

主要人物/中心观点/重要角色

She played a central role in the debate.

她在辩论中起到了重要作用。

4. chief:adj. 最重要的，主要的，首席的.强调最重要的或等级最高的，只作定语。

a chief engineer/judge

总工程师/审判长

The chief difficulty of this project lies in lack of funds.

这个项目的主要困难在于缺少资金。

5. crucial:adj. 决定性的，关键的.指处于某一重要转折点的，强调某事物非常重要，是其他事物依赖的对象。

This new policy is crucial to economic development.

这项新政策对经济发展至关重要。

The work of teachers is crucial in spreading knowledge.

教师的工作对知识的传播起着关键性的作用。

Their support was crucial to the project's success.

他们的支持对项目的成功至关重要。

Negotiations are now at a crucial stage.

目前，谈判正处于关键阶段。

6. important:adj. 重要的，重大的.普通用词，指人有权威、有影响力的，或指事物意义重大、有价值的。

She is obviously an important person.

她显然是个举足轻重的人。

It was one of the most important decisions ever made.

这是所作出的最重大的决定之一。

7. main:adj. 主要的，最重要的.普通用词，多指同类事物中最大、最重要的。

the main force/problem/road/street

主力军/主要问题/主干道/主要街道

She took down the main points of the speech.

她把演讲的要点记了下来。

Snails would, of course, be the main dish.

蜗牛当然会是道主菜。

全部

1·Defence of the realm is crucial.

王国的防御是至关重要的。《柯林斯英汉双解大词典》

2·This last point is crucial.

刚讲的这一点是关键的。《牛津词典》

3·The battle had reached a crucial juncture.

战斗已到了关键时刻。《牛津词典》

4·The next few weeks are going to be crucial.

今后几个星期是关键。《牛津词典》

5·The foreign market was increasingly crucial.

国外的市场越来越关键了。《柯林斯英汉双解大词典》

6·The use of the correct materials was crucial.

使用合适材料是重要的。《柯林斯英汉双解大词典》

7·The crisis is entering a crucial, critical phase.

危机正进入一个至关重要的决定性阶段。《柯林斯英汉双解大词典》

8·The allegiance of uncommitted voters will be crucial.

未表态的投票者的支持将会至关重要。《柯林斯英汉双解大词典》

9·The authorities proved unyielding on one crucial demand.

当局在一点至关重要的要求上态度非常坚决。《柯林斯英汉双解大词典》

10·Money will be crucial to the accomplishment of our objectives.

要实现我们的目标，钱是至关重要的。《牛津词典》

重要的

1·The use of the correct materials was crucial.

使用合适材料是重要的。《柯林斯英汉双解大词典》

2·He's the linchpin of our team and crucial to my long-term plans.

他是我们团队的关键人物，对我的那些长远计划很重要。《柯林斯英汉双解大词典》

3·Artificial dyes continue to play a crucial role today.

人工染料在今天仍然发挥着重要的作用。

4·It has become a crucial part of employees' overall work experience.

它已经成为员工整体工作经验的重要组成部分。

5·Having a large network and some promotional skills may be more crucial.

拥有一个庞大的人际网和一些推销技巧可能更为重要。

至关重要

1·Defence of the realm is crucial.

王国的防御是至关重要的。《柯林斯英汉双解大词典》

2·The crisis is entering a crucial, critical phase.

危机正进入一个至关重要的决定性阶段。《柯林斯英汉双解大词典》

3·The allegiance of uncommitted voters will be crucial.

未表态的投票者的支持将会至关重要。《柯林斯英汉双解大词典》

4·The authorities proved unyielding on one crucial demand.

当局在一点至关重要的要求上态度非常坚决。《柯林斯英汉双解大词典》

5·Money will be crucial to the accomplishment of our objectives.

要实现我们的目标，钱是至关重要的。《牛津词典》

决定性的

1·Diagrams are crucial, since without them, it is difficult to develop an understanding of the model and, hence, the system it represents.

图是决定性的，因为没有它们，理解模型是很困难的，因此理解模型代表的系统也是很困难的。

2·For our purposes, I think it's not crucial.

对于我们的目的，我认为这不是决定性的。

3·It was obvious to both sides that the next campaign season would be crucial.

很明显，对于作战双方而言，下一个战役季节将是决定性的。

4·All you need is to just do it and you will reach a crucial tipping point in which you will go from saying and planning; to doing and proving.

所有你需要做的便是“想做就做”并走向一个人人都在说的、人人都在计划的不论是行动还是提高的决定性转折点。

5·Protein is crucial for recovery and repair, which you'll be needing a lot more of during marathon training.

蛋白质对于修补和复原有决定性的作用，你在马拉松训练中需要补充大量的蛋白质。

关键性的

1·There were, however, a number of crucial flaws in his monetary theory.

然而，他的货币理论中有很多关键性的欠缺。《柯林斯英汉双解大词典》

2·But the cost is positive, and a crucial first step to dealing with climate change, therefore, is to charge people for the carbon they emit.

但是，这种成本能带来积极影响，它是与气候变化作斗争的关键性起步，因此，向排放碳的个体收取费用有合理的理由。

3·But some crucial evidence is still missing.

但是仍然缺乏一些关键性的证据。

4·Organizations need to create a seamless cross-language flow of information for gathering and managing crucial identifying data.

这些组织必须创造一种超越语言的无缝信息流来收集和处理关键性的身份数据。

5·The piece that was found last Friday, which belongs to the very front of the ship, has provided new and crucial clues as to its size and use, however.

这件残骸上周五被挖掘出来，它属于这条船的最前端部分，不过它也为这条船的大小、用途提供了新的关键性的线索。

最关键

1·But economic analysts say that what is just as crucial is that the leaders project a united front and a commitment to coordinate efforts to combat the crisis.

不过经济分析人士认为，最关键的是与会各国领导人让世界看到了一个统一阵线，并保证进行协调一致的努力，战胜危机。

2·It's crucial for Banks to take the long view and consider the value of improved agility as they undertake application renewal.

在实行应用革新的过程中，把目光放长远并考虑提高的灵活性的价值对银行来说是最关键的。

3·This helps operators focus on the most important and crucial problems, based on predefined and configurable criteria.

这可以帮助操作员根据预定义的和可配置的标准，重点关注最重要和最关键的问题。

4·Business visions and goals, along with metrics, those are most important and crucial to the success of the it transformation.

对IT转换的成功最重要和最关键的业务远景和目标，以及指标。

5·Therefore it is crucial to make the link as visible and as obvious as possible.

因此让链接尽可能地显而易见是最关键的。

至关紧要的

1·The next few months will be crucial.

接下来的几个月将至关紧要。

2·Students should not only keep their ambitions in mind, but also seriously strive towards them. Without a clear purpose, one might easily waste crucial years neglecting one's studies.

大学生不应只空谈理想，应该认真地为之奋斗，而没有明确的目标则会让一个人在度过他至关紧要的几年后头脑空空。

3·Actions that are taken by developers and designers during development that are crucial to security but may be difficult to detect as part of the deployment process.

开发人员和设计人员在部署期间所采取的对安全性至关紧要的操作，但是这些操作难以作为部署流程的一部分进行检验。

4·Many of these challenges can put an enterprise's it infrastructure at risk, so ensuring the highest possible level of it security is crucial.

其中许多挑战可以让企业的IT基础设施面临风险，所以确保尽可能最高级别的IT安全是至关紧要的。

5·Working to optimize each of these five components of fitness is crucial to enhancing your overall fitness and general health.

努力优化这五个健康要素中的任何一个，对加强你的全面健康和一般健康都是至关紧要的。

极其重要的

1·It is crucial that we get this right.

我们把这个问题弄明白是极其重要的。《牛津词典》

2·And that, in the modern world of the Internet, is a crucial distinction.

这在现代互联网中，是一个极其重要的特征。

3·Identification and prioritization of risk is the crucial step in defensive competitive intelligence early warning, which provides the bases for later period warning decisions and assessments.

风险识别与排序是反竞争情报早期预警流程中极其重要的一步，它为后期的预警决策及评估提供了依据。

4·Risks of cognitive side-effects with antiepileptic drugs can add to previous damage by surgery or radiotherapy, and therefore appropriate choice and dose of antiepileptic drug is crucial.

我们已经认识到抗癫痫药物的副反应风险可以加重从前的手术或放疗造成的损伤，因此恰当的选择抗癫痫药物及其剂量是极其重要的。

5·Gut bacteria play crucial roles in digesting food and modulating the immune system.

肠道细菌在消化食物和调节免疫系统方面发挥了极其重要的作用。

紧要

1·Any criteria you choose will do, but one might be: Which project was most crucial to helping understand, influence, or just plain implement an important standard?

衡量的标准由您选择，不过我问的标准是：哪个项目对帮助理解、影响或顺利地实现一个重要的标准是最紧要的。

2·He thinks 1415 marks the crucial moment on that path: the year when Henry, pretending to want peace with France, in fact slowly mobilised the whole of England for war.

他认为，1415年标志着这条道路的紧要关头：这一年亨利佯装和法国议和，实际上在慢慢地动员全英国参战。

3·Third, China is at a crucial economic juncture.

第三，中国经济正处在一个紧要关头。

4·Configuration management is important to test management because tracking which builds to test at what time is crucial to testing.

配置管理对于测试管理来说很重要，因为在什么时候对哪一个要测试的版本进行跟踪对测试来说至关紧要。

5·What is crucial at this time is to reassess an earlier situation or decision.

这时候紧要的问题是将之前的状况或决定再重新评估一遍。