必要时

It must be grinded strictly before processing;(2) sulphide iron ore has high tin content, it is necessary to recover tin ore from this mineral.

选别时必须磨到一定的细度；(2)硫铁矿物含锡高，有必要在硫铁矿物中回收锡石。

Proteases and lipases are used in cleaning animal hides, a necessary step in leather production.

皮革生产时，用蛋白酶和脂酶来清洁动物的皮，这是生产的必要的步骤。

The pedal, lock, basket and back seat, ect which can lead to hurt must be removed, otherwise when checking they are removed and kept by the committee technician.

脚撑、锁、篮筐、后座等可能导致伤害的非必要配件请再赛前自行拆卸，否则将在检录前的车辆安全检修时由组委会技师拆除保管。

The enterprises in middle and western regions are more obvious than the western region.

在这里，企业技术创新和企业经济发展是三个名词连缀的短语，在英语中，当超过两个的名词进行连缀时，我们就十分有必要搞清楚他们之间的关系了。

It is a bad habit that evidently applied to war, as well as to denying due process to yobs and suspected terrorists.

这一套在明显用于战争是个坏习惯，就像处理暴民或恐怖嫌疑分子时省略必要的流程一样。

By comparison and Fourier analysis of the waveshapes of the input current with different values of the inductor in the experiment, the valuable references are attained in the same type circuit design.

所以对电感值的计算就显得尤为必要。Boost型APFC电路中的升压电路部分不同于传统的Boost电路。传统Boost型电路的输入电压是直流电，在设计电感值时比较容易。

A new study idea that makes the occupant injury prevention research and CAD/CAE technology on an integrate mathematical model by means of feature theories and feature design technologies was brought, and it is maybe useful if we study automobile passive safety on a new view of point.The conclusions of this thesis included that what are the main factors of airbag-related injuries and the preventive measures, based on the research of the relationships between injury parameters, such as HIC, chest acceleration, neck force, neck moment, femur axial force etc, and impact speed, belt-use, occupant size (50th and 5th), sitting position and so on. The thesis evaluated whether the effectiveness of the airbag can be increased by making the airbag adaptive to the crash conditions, and points out that the size of the ventilation hole has the dominating influence on the performance of the airbag and is a key factor for intelligent airbag, multi-stage and lower-power inflator can cost effectively minimize the risk of injury to occupants from crashes. It is important for the researchers of intelligent airbag to keep the small size unbelted occupants in focus and it is necessary to study deeply the influence of airbag fold patterns and the extremity out-of-position situation. These topics are important in the study of occupant injury prevention and vehicle safety design.

论文研究得出产生气囊损伤的主要原因和防护措施；在研究汽车碰撞速度、安全带使用情况、乘员的体型5~(th和50~、乘员乘坐的位置等不同事故条件作用下，乘员的头部、颈部、胸部和腿部损伤参数变化规律的基础上，论文从能量因素出发，深入研究了安全气囊卸载能力、气体发生器产气能力和气囊折叠对乘员损伤参数的影响，指出起卸载作用的排气孔其截面积是智能型安全气囊最重要的控制参数之一，以及采用降能展开或二次充气气囊有助于提高汽车安全防护性等重要结论；论文在参数分析的基严内容提要2 础上得出的智能型安全气囊应以不佩戴安全带的5乘员作为主要防护目标进行研究、有必要深入研究气囊折叠形式和司机处于极端离位状况时对损伤参数的影响等结论，对深入进行汽车乘员碰撞损伤研究和汽车安全性设计都具有重要的理论和工程实际意义。

When GPS data is displayed on a GIS map,logically the v ehicle point should be displayed on the roads.But because of the effect of error s,there are warps between the true vehicle point and the displayed point o n the map.

AVL系统中GPS信号在GIS地图上显示时，由于各种因素的影响，存在很大的偏差，对这种偏差的校正是十分必要的。

This needs to be provided up-front so that Tokamak can allocate all the required memory before the simulation begins.

这需要直接提供，以致于Tokamak能在模拟器开始时分配所有必要的内存。

In stoppage time, Carvalho picked up a needless booking, tetchily kicking the ball away at a free-kick.

补时阶段，卡瓦略领取不必要的黄牌，他在对方获得任意球时将球踢飞泄愤。

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