必需的

Owing to the exploitation of phosphorite and the unilateral circulation of phosphorus in nature, phosphorus resource is increasingly exhausted.

自然界磷的迁移转化磷是人类和动植物的各种生命活动必需的元素，它在细胞的生命活动中起着关键作用。

Considerableworks are necessary–a special set of tools, an apparatus of platina,leaden chambers, unassailable by the acid, and in which the transformationis performed, etc.

有不少设备都是必需的，如：一套特殊的工具、白金的仪器、不怕酸类腐蚀的铅室——用来在里面进行化学变化——等等。

The baculovirus expression system, utilizing the strong polyhedrin gene promoter of the Autographa californica nuclear polyhedrosis virus , has become an important tool for protein production in the field of molecular biology.

由于核型多角体杆状病毒的多角体蛋白不是病毒复制必需的蛋白，利用转录多角体蛋白基因的强启动子可以高效表达外源蛋白，包括原核和真核基因编码的蛋白。

A need is something you can't live without and a want is more of a preference.

需要的东西是你生活必需的，而想要的东西是自己更喜欢的。

Then is a factual premiss, saying that a certain disposition is necessary, sufficient, or at least helpful in achieving a certain end (or living by a certain principle); it will usually be of a kind that depends on experience and science for its verification, but in some theories of education it might come from metaphysics or theology.

那么，作为一个事实前提，说明了一个确定的性状是必需的、足够的，或至少有益于实现特定的目标（或存在依靠一特定的原则）；它通常将属于一种依赖经验和科学来证实，但是，在有的教育理论中它可能来自形而上学或神学。

It is understandable to think, but it's necessary to predict prudently any situation.

想当然的倾向是可以理解的，但是，理智地估计任何情形的情况是完全必需的。

Although he arrived at the same time as a senatorial delegation from the New Republic, led by Baron Jonas Stern and the Bothan Borsk Fey'lya, Thrawn seems to have already regarded Sluis Van as lost to the Empire in diplomatic terms: his modest intention was to acquire a Star Destroyer under construction in the docks, and to gather intelligence in anticipation of a future military reconquest of the system.

与此同时，由乔纳斯·斯特恩男爵、波森人博斯克·费利亚两人所带领的新共和议院授权代表团也到达了该地。在外交措辞上，索龙看起来似乎已经不再将斯路易斯·范视作帝国治下。他谦逊的态度下掩藏的真实目的其实是获得船坞中正在兴建的一艘歼星舰，以及将来能够再度夺回这一星系而必需的相应情报。

NASA took the reductionist approach: find the simplest units of life that can produce the required oxygen, protein, and vitamins for human consumption.

NASA采用的是简化的方法：寻找能够生产出人类消耗所必需的氧气、蛋白质以及维他命的最简单的组件。

You know what is necessary, but your response time is affected by your surroundings.

你们知道哪些是必需的，但是你们的反应时长是受到你们的周围影响的。

BACKGROUND: Nerve root retractor is necessary apparatus in nucleus pulposus removal of lumbar intervertebral disc protrusion and lumbar spinal fusion.

摘要背景：神经根拉钩是腰椎间盘突出症髓核摘除和腰椎融合术中必需的器械，传统的神经根拉钩无法量化神经根的拉力，容易引起神经根的过度牵拉。

It has been put forward that there exists single Ball point and double Ball points on the symmetrical connecting-rod curves of equilateral mechanisms.

从鲍尔点的形成原理出发，分析对称连杆曲线上鲍尔点的产生条件，提出等边机构的对称连杆曲线上有单鲍尔点和双鲍尔点。

The factory affiliated to the Group primarily manufactures multiple-purpose pincers, baking kits, knives, scissors, kitchenware, gardening tools and beauty care kits as well as other hardware tools, the annual production value of which reaches US$ 30 million dollars.

集团所属工厂主要生产多用钳、烤具、刀具、剪刀、厨具、花园工具、美容套等五金产品，年生产总值3000万美元，产品价廉物美、选料上乘、质量保证，深受国内外客户的青睐