前言

A sentence that does not cohere is hard to understand.

一个句子，前言不搭后语，就很难理解。

Due to the constraint of both high current and high speed, it is difficult to commutate for high-speed and high-current DC machine .

1前言 换向问题是直流电机的固有问题，换向过程十分复杂，影响换向的因数很多。

The compilatory "Glossa Ordinaria" was widely read and highly esteemed as a treasury of sacred learning during the Middle Ages; it embodied the prefaces in which the Doctor of Bethlehem had written in terms derogatory to the deuteros, and thus perpetuated and diffused his unfriendly opinion.

编纂" glossa ordinaria "被广泛阅读和高度评价，作为财政部的神圣学习，在中世纪，它体现了前言，其中博士伯利恒曾写信条款贬到deuteros ，从而延续和扩散，他不友善的舆论。

In this paper,a novel immobilization method of urease based on the strong interaction between concanavalin and glycoprotein was developed through Con A and urease assembled layer by layer.

1前言尿素的测定在临床检验、食品化学、环境监测中都具有十分重要的意义，因而有必要研究一种简单、快速、价廉的检测尿素的方法。

Like Chrysler, GM is arguing with bondholders over the concession terms.

前言：这次始于发达国家的危机中，IMF确实采取了和过去截然不同的态度。

Preamble of the optical phase conjugation of the background and significance of topics and papers done on the contents in detail.

前言部分对光学相位共轭的选题背景和意义以及论文内容安排做了详细的阐述。

A new radiator(strengthened tubular and corrugate fin type radiator) was presented in the paper.

1前言冷却系统是内燃机车的重要组成部分，其作用是使机车维持在最佳工作温度。

A new separator used to remove the dispersive oil droplets from waste water of oil fields and oil refineries was developed with inclined corrugate plates as packing.

1前言 对油田或炼油厂来说，污水处理首先是除油，随着生产发展和环境保护日益严格的要求，迫切需要开发高效含油污水处理设备。

The author introduces background about generation of countability in topology and status about the research and the development of count-ability on lattice-valued topological spaces, and gives the main problems to be soled.

文章由六部分组成：第一部分是前言，作者简单介绍了拓扑空间中可数性的产生背景，格值拓扑空间可数性的研究发展情况，给出本文主要的研究问题。

It is a coursebook of elementary practice that no beginners should skip over.

我觉得这个句子是在书评或者前言里，所以应当符合英文的习惯

I can not make it blossom and suits me

我不能让树为我开花

When temperatures are above approximately 80 °C discolouration of the raceways or rolling elements is a frequent feature.

当温度高于 80 °C 左右时，滚道或滚动元件褪色是很常见的特征。