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。