Many scientists believe that a huge object from space hit Earth about 65 million years ago.

VOA: special.2009.01.20

Suppose the planet were hit by a comet-- this happened--something like this happened sixty-five million years ago, so it could happen again.

假设这个星球被一颗彗星击中-,这样的事，大约六千五百万年前,发生过，所以它还可能再发生。

耶鲁公开课 - 金融市场课程节选

This Cambridge History of Food talks about three separate primary phases in human food evolution: one beginning a million and a half years ago, another about 700,000 years ago, and then the 10,000 year ago one that I talked about just a moment ago.

剑桥饮食史》描述了,人类饮食结构演化过程中的三个不同阶段,其一,始于一百五十万年前,其二,距今约七十万年,其三,距今一万年,我们刚讨论过了

耶鲁公开课 - 关于食物的心理学、生物学和政治学课程节选

A large meteorite hit the area four thousand million years ago.

VOA: special.2009.07.29

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

"It's a meat-eating dinosaur. It would have lived in the Late Jurassic period about a 140,150 million years ago.

VOA: standard.2009.12.08