1.crude oil 原油

例句：A crude oil slick quickly spreads out over water.

原油泄露后的浮油很快在水面上扩散开来。

2.at least 至少

例句：Try to eat at least four slices of bread a day.

每天尽量至少吃4片面包。

3.on record 记录在案的

例句：It's the shortest election campaign on record.

这是史上为期最短的一次竞选活动。

4.man-made 人造的

例句：Man-made and natural disasters have disrupted the government's economic plans.

人为和自然灾害打乱了政府的经济计划。