They farm tilapia - mostly in China. Sporns says the U.S.has an international certification process that is rigorous and will catch potential problems.

VOA: standard.2010.05.27

It's a pretty state of affairs, in his view, when the most rigorous thinking that's being done about literature is being done in popular journals.

他认为，关于文学的严肃的思考大多,被发表在流行杂志上很不妥当。

耶鲁公开课 - 文学理论导论课程节选

Now to make that lower-of-the-two-prices comment a little bit more rigorous, let's figure out what the demand actually is for these firms.

为了说明两者价格较低者,具体是什么意思,先来解决这些公司真正的需求量是什么

耶鲁公开课 - 博弈论课程节选

And at the same time it's rigorous, based on research.

同时又是严格的，以研究为基础。

哈佛公开课 - 幸福课课程节选

If you want a slightly tougher book, more rigorous book, try Joel Watson's book, Strategies.

要是你想要一本更难更有挑战的,试试乔尔?沃森的《策略》

耶鲁公开课 - 博弈论课程节选