Accidents occur mainly due to human error.

事故主要由于人为错误发生。

Twenty percent of all crash fatalities and 40 percent of accidents occur at intersections.

20%的撞车和40%的事故发生在十字路口。

Objective: To increase the speed of personnel radiation monitoring should nuclear accidents occur aboard ships.

目的：提高在舰船核事故条件下对人员进行应急辐射监测的速度。

Objective : To increase the speed of personnel radiation monitoring should nuclear accidents occur aboard ships.

目的: 提高在舰船核事故条件下对人员进行应急辐射监测的速度.

Objective:To increase the speed of personnel radiation monitoring should nuclear accidents occur aboard ships.

目的：提高在舰船核事故条件下对人员进行应急辐射监测的速度。

Some sources of pollution, such as nuclear power plants or oil tankers, can produce widespread and potentially hazardous releases when accidents occur.

一些污染源，如核电厂或油轮，可以产生广泛和有潜在危险的事故发生时释放。

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。

At present, the situation of safe production of coal mine is very serious in our country, and mining accidents occur frequently in recent years which cause very enormous loss of life and property.

目前，我国的煤矿安全生产形势十分严峻，特别是近年来重大矿难时有发生，造成了巨大的生命和财产损失。