I am not sure, but I'll try my best.

Aviation safety studies have shown that approximately 90% of all aviation accidents occur during the first two minutes or the last four minutes of flight.

航空安全研究显示所有的飞行事故中大约有90%都发生在开始两分钟或者最后四分钟的时候。

α am < α am, Throughout this paper, we assume that the peak values of response occur on the first stroke of the system motion.

本文的基础是所谓首程显峰，假定即系统在速度冲击V下的响应峰值d m和a m出现在第一行程中。

Most leaks occur within the first few meters and you may be able to save the camera if you see a leak early enough.

大多数漏水情况就会出现在最初的几米，如果你及时发现漏水，可以尽快挽救你的相机。

Since crossing over can occur during the first meiotic division, it does allow for some genetic variation in the offspring.

在第一次减数分裂的过程中可以发生交换现象，因而在后代中有遗传变化。

It says an estimated 37 percent of deaths among children occur in the first month of life, and most in the first week of life.

报告表示，在儿童中，估计有37%的死亡发生在出生后第一个月，大多数在出生后第一星期。

In the visible light region, the maximal one-photon absorption strengths of the molecules occur in the first excited state.

在低能量范围内，对于D-π-A型分子，分子的单光子吸收强度和双光子吸收截面最大值都发生在分子的第一激发态。

Well above two thirds of these deaths, often associated with inappropriate feeding practices, occur during the first year of life.

其中三分之二以上的死亡通常与一岁以前不合理的喂养方式有关。

Shuori solar eclipse will occur in that first day of the Lunar New Year ( New Moon).

日食必发生在朔日，即农历的初一（朔）。

Three misprints occur on the first page.

第一页有三个地方印错。

Most infant deaths and hospitalizations now occur in the first two months of life.

现在，因百日咳死亡或住院的婴幼儿大部分发生在头两个月。

Many words that occur in the first edition are used in new senses and enter into new compounds.

第一版中的许多词现已用于新义并复合成新词。

Three quarters of all newborn deaths occur in the first week of life.

所有新生儿死亡中有四分之三发生在生命第一周。

Technically, this step need not occur first, but it needs to occur early; it should be obvious that you should create the database before any application code, even automatically generated code.

技术上这个步骤不必最先进行，不过需要在早期完成；应该在编写任何应用程序代码（甚至是自动生成的代码）之前创建数据库，这应该是显然的。

The read-first technique involves refactoring ( or writing) the application logic and workflow so that all processing and read operations occur first, outside of a transaction's scope.

先读取技巧涉及重构（或编写）应用程序逻辑和工作流，以便所有的处理和读取操作在事务作用域的外部首先发生。

Conclusions: In diabetic retinopathy, the changes in vascular morphology occur first, and the expression of growth factor follows.

结论：糖尿病视网膜病变时血管器质性改变在先，而生长因子表达在后。

Or services that the process invokes and invoke the process ( where either may occur first).

或者既由流程调用又调用流程的服务（首先出现哪种情况都有可能）。

Corpus-based study shows that chunks are universal and occur frequently in language.

基于语料库的研究表明，语言中普遍存在着重现率很高的语块。

However there remains a serious problem on school safety, Accidents occur frequently on campus.

然而，近年来，我国校园安全问题依然严重存在，校园安全事故频频发生。

Road traffic accidents occur frequently, which caused serious personal injury and economic losses.

道路交通事故频繁发生，给人们造成了严重的人身伤害和经济损失。

In recent ten years, accidents induced by fire and explosion occur frequently.

近十年来，国内外火灾和爆炸事件时有发生。