We need to understand the context in which these accidents occur.

According to a Boeing analysis, only 9 percent of fatal accidents occur at cruising altitude.

根据一份波音公司的分析，只有9%的致命事故发生在巡航高度。

Most highway accidents occur in the left lane.

多数高速公路事故发生在左车道。

When the steel cools to727 ℃( 1341 ℉), several changes occur simultaneously.

当钢冷却到727℃（1341℉）时，将同时发生若干变化。

As we grow older, changes occur in our cells that reduce the number of times they can reproduce.

随着我们逐渐变老，细胞发生变化，它们复制自身的次数减少。

Spread the word body to produce a small minority of the tendency, characteristic of Ci corresponding changes occur.

词体传播产生出小众化的倾向，词体特征发生相应的改变。

The changes occur in the outer protein of the virus, the target of neutralizing antibodies.

变化在病毒的外部蛋白质中产生，它是中和抗体的目标。

Within a site, domain controllers synchronize with each other based on notifications when changes occur.

在某个站点内，域控制器在发生更改时根据通知彼此进行同步。

When changes occur to some file types and folders, the application domain restarts.

如果某些文件类型和文件夹发生了更改，应用程序域将重新启动。

In Rails applications, schema changes occur through migrations.

在Rails应用程序中，模式的更改是通过迁移发生的。

What body changes occur when the sperm whale drives?

抹香鲸潜入水中时，身体会发生什么变化？

Most of these changes occur randomly and spontaneously rather than manual operations.

这些遗传改变中的大部分都不是人工操作的结果，而是随机的遗传改变。

Such changes occur in individuals independently of their own private information signals, he says.

这种改变会发生在不受本人信息信号影响的个体身上，他说。

These changes occur at 4 to 6 month old and go on to the following months.

两种蛋白变化初始期为4～6月龄，并于随后月龄持续存在波动现象。

Remember: a true friend doesn't flee when changes occur.

记住：真正是朋友是在发生变故时仍留在你身边。

Many pathologic and physiologic changes occur after brain injury.

脑损伤（brain injury）后脑组织发生的一系列病理、生理和生化改变，由许多基因、细胞因子参与调节并影响着损伤程度的转归。

No changes occur to the database file.

不对数据库文件进行任何更改。

That's the way most changes occur.

这就是大多数更改的实施方式。

Major changes occur in the external conditions of the company's production and management;

（六）公司生产经营的外部条件发生的重大变化；

With a change in consciousness, actual chemical changes occur.

靠意识知觉的变化，实际的化学变化出现了。

Other researchers at Penn have shown that, in mammals, synaptic changes occur during sleep and that deprivation of sleep results in a disruption of these synaptic changes.

Penn睡眠研究中心的其他研究者发现，哺乳动物在睡眠过程中，有突触变化发生；如果缺少睡眠则突触变化就会中断。