Another senior defense official, who spoke on condition of anonymity, said last week that any change in the complex series of agreements could unravel the entire plan, which was 15 years in the making.

VOA: standard.2009.10.18

In complex organisms like humans there's another step that we're still only learning about now.

在像人类这样的复杂有机体中,还有另一个我们至今仍未完全了解的步骤

耶鲁公开课 - 生物医学工程探索课程节选

In complex organisms like humans there's another step that we're still only learning about now.

在像人类这样的复杂有机体中,还有另一个我们至今仍未完全了解的步骤

耶鲁公开课 - 生物医学工程探索课程节选