必需的

Water supply of city is its vital arteries and offers necessary condition for producing and living. It is the key factor of city development and also the important factor of society stableness.

城市供水是城市的命脉，它为城市的生产、生活提供着必需的条件，是制约城市发展的决定性因素，甚至也构成了关系社会安定的重要因素。

Poor soils, uneven terrain, and a severe climate led to typical subsistence?farming, the growth of only those crops necessary for family maintenance.

贫瘠的土壤、崎岖的地表以及恶劣的气候造成典型的生存性农业，仅能种植维持农场家庭生存所必需的作物。

Objective:To set up a resonance light scattering method for determination of trace copper in water sample with the sulfhydryl cotton separation-enrichment method.

铜是工业上广泛应用的金属，在环境中分布很广；Cu也是人体及动植物所必需的微量元素，对机体的新陈代谢有重要的调节作用；因此，研究用于测定Cu的高灵敏度方法十分必要。

Process water technology is an important part and necessary technology sustentation in pharmaceutical industry. It must reach the quality target of pharmacopoeia, like other materials in the drug producing.

工艺用水技术是制药工业的重要组成及必需的技术支撑，必须同药品生产的其它原辅材料一样，达到药典规定的质量指标。

The telemetry sub is the core of organization and management of the system,which provides necessary support of software and hardware for data acquisition, processing andtransmission;the ultrasonic imaging televiewer visually presents the condition of interwall ofcasing and the borehole wall;the acoustic caliper quickly and quantitatively detects the status ofinterwall of casing and borehole wall;the azimuth logging tool provides the casing damagelocation demanded by ultrasonic imaging televiewer and acoustic caliper.

遥测短接为该系统的组织管理核心，为各功能短接提供数据采集、处理及传输等所必需的软硬件支持；超声成像仪可直观显示套管内壁或井壁的自然状况，声波井径仪可快速定量检测套管内壁或井壁的状况；方位仪为超声成像仪及声波井径仪提供所需的套损方位。

During the mitosis, the correct separation of sister chromatids is necessary in normal transition from anaphase to telophase and it guarantees exact distribution of DNA. The non-disjuction is the important reason for forming the aneuploid.

在有丝分裂时，姐妹染色单体的正确分离既起到保证遗传物质准确分配的作用，又是分裂细胞从后期向末期过渡所必需的；而姐妹染色单体不分离则是产生非整倍体细胞的重要原因。

The tendance to take things for granted,but the need for one to rationally evaluate the circumstances of any situation is essential.

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。

A ternary operation; a treble row of red beads; overcrowding made triple sessions necessary; triple time has three beats per measure; triplex windows.

三重操作；三排红色的珠子；要容纳过多的人使三次会议成为必需的；三拍子的每一小节有三折；三重窗户。

And we continue to test them virus load remaining, so the data to make good decision at week 24 should be available on routine test.

我们应该检测他们的病毒载量。因此24周时的数据对做出好的决定是必需的，并且应该作为常规检查。

This is because physical activities are necessary for good health while intellectual activities are beneficial to one's mind.

这是因为身体的活动是良好健康所必需的智力活动的同时，有利于人的心。

On the other hand, the more important thing is because the urban housing is a kind of heterogeneity products.

另一方面，更重要的是由于城市住房是一种异质性产品。

Climate histogram is the fall that collects place measure calm value, cent serves as cross axle for a few equal interval, the area that the frequency that the value appears according to place is accumulated and becomes will be determined inside each interval, discharge the graph that rise with post, also be called histogram.

气候直方图是将所收集的降水量测定值，分为几个相等的区间作为横轴，并将各区间内所测定值依所出现的次数累积而成的面积，用柱子排起来的图形，也叫做柱状图。