必不可少

Food Sources Proteins are described as essential and nonessential proteins or amino acids.

食物来源的蛋白质称为必不可少的非蛋白质或氨基酸。

Thus, iron is essential for normal physiological function.

因此，体内保持一定数量的铁对于正常生理功能是必不可少的。

Mitochondrial DNA contains 37 genes, all of which are essential for normal mitochondrial function.

线粒体DNA含有37个基因，所有这一切都是必不可少的正常线粒体功能。

Language is obviously essential for human beings, but it is not the whole story of human communication.

语言显然是必不可少的人，但它并不是整个故事的人际沟通。

Especially, the development trend of numerical control system simulation is discussed.

从而得出结论：仿真技术是数控系统中是必不可少的手段，将会更加飞速的发展。

At the same time calculation of numerical value is a necessary link solving the linear system of equations, which is a very important question in calculation of numerical value.

数值计算是科学计算中的一个必不可少的环节，而在数值计算中，一类很重要的问题就是线性方程组的求解。

In ancient times at a wedding, six etiquette were necessary for the nuptials.

古代婚姻有"六礼"，这对婚姻成立必不可少。

Good nutrition is essential for good health.

好的营养是健康必不可少的。

It's obligatory, she said.

这必不可少，她说。

These are indispensable for the subsistence of its people and are obtainable only from abroad.

这些东西在人民生活中必不可少，而且必须要从外国进口。

But we don't care about Battlegrounds.

但我们并不在乎沙场中的显露。

Ah! don't mention it, the butcher's shop is a horror.

啊！不用提了。提到肉，真是糟透了。