By Tom Burridge, BBC News

媒体英语会带大家一起学习BBC撰稿人在报道世界大事时常用到的单词和短语。

Background: IBM超级电脑“沃森”(Watson) 击败了美国《危险边缘》节目历史上最成功的两位选手。被击败的两位选手其中一位在此之前是连赢74场比赛的纪录保持者。

Jeopardy is one of America's oldest and most popular quiz shows. But this time, inside the brightly-lit studio, a contest billed as 'man versus machine' - the programme's producers pitted two of their most successful contestants ever against a computer. Known as Watson, the computer is a giant piece of hardware, equivalent in size to several fridges. And over three programmes, Watson beat his human contenders with ease.

In a split-second, Watson is able to digest the question and try and match it against huge amounts of information it has at its disposal. It very quickly assesses how good a match it thinks it has and buzzes either very quickly, or not so quickly, reflecting how confident it is that it has the right answer.

Watson is also able to notice nuances in language, between say 'bat' the animal and 'bat' used in sports. On a prime-time US TV show with millions of viewers it was great publicity for IBM. But the company says Watson the computer is an IT genius and a breakthrough in computing.