必需的

Optical properties of the atmosphere including sky background radiation and surface reflectance are basic physical quantities for atmospheric radiative transfer, light propagation research, and can also find important application in remote sensing, adaptive optics, free-space optical communication, etc.

大气光学特性（包括地表的光学特性和天空背景辐射特性）是光波在大气中传播和大气辐射传输研究必需的基础物理性质，在气象、气候和天文观测等基础和应用研究以及自适应光学技术、自由空间光通讯等光电工程应用中具有十分重要的作用。

While they enjoy the comfort and banal luxury of their dwelling, they do not realize that they are deprived of the necessities of life.

在享受自己住宅的舒适和庸俗的豪华时，却没有意识到被剥夺了生活所必需的东西。

Barley is the main stuff of beer brewing and chromium is a vital trace element to human. Potassium chromium sulfate was added to the water during the barley infusion and enriched-Cr malt was executed.

啤酒酿造的主要原料是大麦，铬是人体必需的一种微量元素，本文在浸麦过程中用KCr(SO_4)_2处理麦芽，制成了富铬麦芽，研究了铬对麦芽生理生化特性及成品麦芽质量的影响。

I believe talent is not essential to be a good artist. Hard work is.

我认为，作为一个好的画家天赋不是必需的，而勤奋是必要的。

Just as your clothing is a necessity as you go out into the world, let it be equally indispensable for you to put on Jesus Christ, to abide in Him and walk with Him all the day.

当你要去与世人接触的时候，衣服怎样是你所必需的；但愿披戴基督，住在他里面，整天与他同行，对你也同样是不可缺少的。

More and more, it's becoming a must in your profession.

越来越多的，它成为你的专业必需的。

The child's mother replied:"Yes, chewing betel, With me is has become a compulsory habit."

孩子的母亲回答说："是的，嚼萎叶，这已经变成了我的一个必需的习惯。"

No special operator or factory calibration or circuit tweak is required to bring keys into operation, except for a gain and threshold batch setup which can be performed in seconds from a file saved on a PC.

没有特别的运营商或工厂校准或调整是必需的电路，使操作键，除了一个批次设置增益和阈值可在几秒钟内完成从PC上保存的文件。

In order to grow the official burnet plant needs moist meadows.

为使这种蝴蝶产卵和生长所必需的official burnet plant有足够的生长量，需要湿润的草地。

Rhizomes of canna comprise abundant starch, protein, amino acid and many kinds of microelement.

美人蕉根茎含有丰富的淀粉，除此之外，还含有3.5%的蛋白质和人体必需的八种氨基酸，还含有多种矿物质和微量元素。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。