The standardcriterion for the survival of a species is its success in competing with other species and adapting to slowly changing environments.
一个物种生存下来的标准是它能否成功地与其他物种竞争并适应缓慢变化的环境。
2
The expressive power of XQuery is comparable to the criterionof "relational completeness" defined for database query languages, though no such formal standard has been defined for an XML data model.