必需的

It is requested, but not required, that you contact the authors of the Document well before redistributing any large number of copies, to give them a chance to provide you with an updated version of the Document.

这是要求，但不是必需的，您与作者的文件以及重新分配之前的任何大量的复制品，让他们有机会为您提供了一个更新版本的文件。

It also repackages long messages when necessary into small packets for transmission and, at the receiving end, rebuilds packets into the original message.

它也再包装长的信息当必需的进入小的小包之内为传输和，在那接管结束，再建小包进入最初的信息。

It was proved through experiment that optimum passive numerical shimming can achieve a high level in superconducting NMR imaging magnets and it can be realized very easily and very economically. Field regression is not absolutely necessary in the technique of optimum passive numerical shimming, but it is useful to know the structure of the field error Bz'.

磁场回归在超导核磁共振成像主磁体的无源数值匀场技术中虽然并不是绝对必需的，但在对主磁体进行无源数值匀场时，如能知道成像空间内不均匀磁场的磁场偏差B〓的结构，也是非常有用的。

The gas turbine engine windmilling is a state that when the engine doesn t work,the rotors temporarily operate at a sub-steady rotating speed due to the airflow ram and the co-work of aerodynamics,rotor inertia and drag torque.

由于很多燃气涡轮发动机都缺乏计算风车特性必需的低转速状态的部件特性，给计算发动机风车状态的特性带来了很大的困难。

Two single packages are necessary and may be the only way to get through customs.

两个独立的包装是必需的，这也可能是惟一的可以通过海关的方法。

The public interest can best be served by an improvement in soil absorption system performance.

因为没有实用的替代该必需的处理系统的系统，人们只能通过改进土壤吸收系统的

This is the enemy, well aware that it attacked the Northeast China, attacked the Soviet Union depot base, northeast of Fuyuan, human, northeast of the iron and coal and other raw materials are necessary for its operations.

这是敌人深知东北是它进攻中国内地，进攻苏联的兵站基地，东北的富源、人力，东北的煤铁和其他原料都是它作战所必需的。

The brake equipment was necessary for ensuring the safety of the train running, and the brake beam was one of the key parts in the foundation brake rigging, whose safety and reliability Playan important role in the running of train safely.

制动装置是保证列车安全运行所必需的，而制动梁是基础制动装置中的关键零部件之一，它的安全性、可靠性对列车的运行安全起重要的作用。

"It's absolutely essential that these photos be released so the public can examine for itself the torture and abuse that was conducted in its name," ACLU attorney Amrit Singh said.

&公布照片绝对是必需的，这样公众才能自己核查那些以他们的名义所进行的酷刑和虐待&，美国公民自由联盟的代理人Amrit Singh说。

JA is a crucial signal molecule in inducing cambia to differentiate the secondary laticifer, and a local high level of JA in cooperating with other plant hormones, especially cytokinin, is prerequisite for the secondary laticifer differentiation.

研究表明，茉莉酸是诱导乳管分化的关键信号分子，局部高水平的茉莉酸是诱导维管形成层细胞分化次生乳管所必需的，同时需要其它激素的协同作用。

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。