必要时

When we enquire to Italian friend, his answer is:"Mini car price is low, cover an area of little, save oil again, not was necessary to be face and floriferous money will buy high-grade car ".

当我们向意大利朋友询问时，他的答复是：&微型轿车价格低，占地少，又省油，没有必要为面子而多花钱来购买高档车&。

And the valet, who had begun to attempt a brogue out of admiration for his new master, made requisite answer in a combination of Geechee and County Meath that would have puzzled anyone except those two alone.

千万不要把玩牌和威士忌混为一谈，除非你早就戒酒了，当天晚上波克服侍杰拉尔德上床睡觉时，杰拉尔德严肃地对他这样说，这位管家由于崇拜主人正开始在学习一种土腔，便用一种基希和米思郡的混合腔调作了必要的回答，当然这种腔调只有他们两个人理解，别人听来是莫名其妙的。

The first person who appeared upon the steep stone steps was a boy in corduroy trousers and a dark linen smock-frock, who shambled down the stairs with a good deal of unnecessary clatter of his hobnailed shoes, and who was red in the face from the exertion of blowing the bellows of the old organ.

首先出现在很陡的石级上的，是一个男孩，他穿着灯芯绒裤子和黑色亚麻布长罩衫，拖拖沓沓地走下石级时，钉着平头钉的靴子弄出了很多不必要的喀啦喀啦的声音，他刚才使劲儿吹管风琴的风箱，脸还涨得通红哩。

The author consider that it is mandatory to design the humeral components fitting the feature of the humeri of the Chinese and diversifying the size, consider the difference of gender on designing and selecting of prostheses.

有必要设计符合国人肱骨解剖特点的假体，假体尺寸规格应多样化，并且在设计和选择假体时需考虑性别差异。

It is necessary and advisable to preserve intercostobrachial nerve during the axillary lymph nodes dissection for stage Ⅰ,Ⅱbreast carcinoma.

乳腺癌腋窝淋巴结清扫术时保留ICBN可以明显减少术后患侧上臂内侧和腋下感觉异常及疼痛，Ⅰ、Ⅱ期乳腺癌腋窝淋巴结清扫术中保留ICBN是必要和可行的。

If you read him, you should understand him, because in the past he complimented you in order to get something that he needed, whereas now that you don't have powers, he doesn't have to intonate whatever hymns for you.

你读他时，千万要理解他。因为他过去是为了某种需要而赞美你，现在你没有那种功力了，也就没有必要再为你吟唱什么赞美诗了。

If you read him,凬 you should understand him,刃 because in the past he complimented you in order to get something that he needed,凼 whereas now that you don't have powers,凵 he doesn't have to intonate whatever hymns for you.

你读他时，刍千万要理解他。凞因为他过去是为了某种需要而赞美你，刚现在你没有那种功力了，刁也就没有必要再为你吟唱什么赞美诗了。

If you read him,凾 you should understand him,凴 because in the past he complimented you in order to get something that he needed,凇 whereas now that you don't have powers,刧 he doesn't have to intonate whatever hymns for you.

你读他时，凤千万要理解他。凤因为他过去是为了某种需要而赞美你，击现在你没有那种功力了，凲也就没有必要再为你吟唱什么赞美诗了。

Modern systems consist of one or more computer-controlled metering pumps that can be programmed to vary the ratio of mobile phase components, as is required for gradient chromatography, or to mix isocratic mobile phases (i.e., mobile phases having a fixed ratio of solvents).

泵系统—HPLC 泵系统通过高压管路和设备将储液系统的流动相按设定的流量精确地输送通过柱子，最新的泵系统由一台或更多的计算机测量控制泵使得流动相组分能够按照程序变化改变比例，如有必要，可以进行梯度洗脱或混合均匀的流动相（i.e。，流动相可以是混合比例的溶液），然而，当操作压力达到或高于5000 psi，流速达到10ml/min的典型值时，预混合均匀的流动相各成分的比例就比泵控制的更精确。

Pumping Systems—HPLC pumping systems deliver metered amounts of mobile phase from the solvent reservoirs to the column through high-pressure tubing and fittings. Modern systems consist of one or more computer-controlled metering pumps that can be programmed to vary the ratio of mobile phase components, as is required for gradient chromatography, or to mix isocratic mobile phases (i.e., mobile phases having a fixed ratio of solvents). However, the proportion of ingredients in premixed isocratic mobile phases can be more accurately controlled than in those delivered by most pumping systems. Operating pressures up to 5000 psi or higher, with delivery rates up to about 10 mL per minute are typical.

泵系统—HPLC 泵系统通过高压管路和设备将储液系统的流动相按设定的流量精确地输送通过柱子，最新的泵系统由一台或更多的计算机测量控制泵使得流动相组分能够按照程序变化改变比例，如有必要，可以进行梯度洗脱或混合均匀的流动相（i.e。，流动相可以是混合比例的溶液），然而，当操作压力达到或高于5000 psi，流速达到10ml/min的典型值时，预混合均匀的流动相各成分的比例就比泵控制的更精确。

In the negative and interrogative forms, of course, this is identical to the non-emphatic forms.

。但是，在否定句或疑问句里，这种带有"do"的方法表达的效果却没有什么强调的意思。

Go down on one's knees;kneel down

屈膝跪下。。。下跪祈祷