He wants to let the Bush administration's tax cuts for the wealthiest Americans end next year, replaced by a middle-class tax cut.

VOA: special.2009.02.27

As long as it was not abrupt, right? I may take my scissors, and cut out a foot in the middle.

这个过程并不是突然的，对吗？，我拿出一把剪刀，这时减掉中间的一英尺。

耶鲁公开课 - 死亡课程节选

When it cuts it leaves sticky ends or un-base paired single stranded regions on each end of the part its cut and that's just a property of many restriction enzymes; not all, some cut blunt,just right down the middle.

它切割后会留下两个粘性末端,或者未配对的单链部分,这是许多限制性内切酶的特性,但不是全部,有些限制性内切酶是从中间钝切的

耶鲁公开课 - 生物医学工程探索课程节选