Authorities say they quickly killed two of the gunmen, but two others continued to fire machine guns in the extended battle in Pul-i-Alam, Witnesses say U.S.military helicopters were part of the response force, and one aircraft fired a rocket into a multi-story building which the insurgents had seized, used to launch their attack and had rigged with explosives.

VOA: standard.2009.08.10

We talked about last time that part of the process of going from this single cell to multi cellular many celled organisms like we are is cell division.

我们上节课说过,从一个单细胞分裂形成大量细胞,构成的器官的过程,叫做细胞分裂

耶鲁公开课 - 生物医学工程探索课程节选

We talked about last time that part of the process of going from this single cell to multi cellular many celled organisms like we are is cell division.

我们上节课说过,从一个单细胞分裂形成大量细胞,构成的器官的过程,叫做细胞分裂

耶鲁公开课 - 生物医学工程探索课程节选