VOA慢速英语:A Victory For Computers as Watson Wins ‘Jeopardy!’

过去完成时

过去完成时一定要以一个过去时态在铺垫，这个动作一定要发生在had done之后

until：直到什么时候为止，直到什么时候才
until，在后面一个从句之前发生了主句
until,主句和从句两个都用一般过去时对，主句和从句然后一个用过去完成是也对

I had not understood the problem until he explained it.

2.The IBM computer proved to be more knowledgeable in every category, including the arts, popular culture and science.

prove to be证明是,判明...是

例句：That rumour was prove to be real afterwards.
      那谣言后来被证明是真的。

3.They compared it to a Super Bowl for the information technology industry.

compare to把…比作, 喻为

例句：Shakespeare compared the world to a stage.
      莎士比亚把世界比作舞台。

4.Roger Norton says the very nature of the game makes Watson's performance even more extraordinary.

very用作形容词，只用于名词前作定语，不用作表语，其意为“正是”、“恰是”，通常要与 the, this, that, my, your 等连用。如：

You are the very man I want to see. 你正是我想要见的人。

At that very moment the phone rang. 就在那时电话铃响了。

5.The ambiguity that's in those answers is very, very difficult for humans to understand, never mind a computer to understand.

never mind更不用说

6.And then to be able to take that, try to understand it, then go off and search its vast amount of data that it has and do the appropriate analytics and come up with not only an answer but also a confidence level associated with that answer – very, very impressive.

come up with想出, 提出

例句：I hope you can come up with a better plan than this.
      我希望你们能提出一个比这个更好的计划。