But it has taken on new urgency,coming one day after the World Health Organization raised its global swine flu alert to Phase 4 on the six-point scale.

VOA: standard.2009.04.28

Phase One, the million and a half years ago, in the early--in the late--Miocene and early Pleistocene phases, there was shift where people were less likely to be just going out and gathering foods from every place they could find it.

第一阶段,一百五十万年前,在整个中新世以及更新世的早期,情况开始转变,人们不光靠,出门四处搜集食物

耶鲁公开课 - 关于食物的心理学、生物学和政治学课程节选