Giant faces of four great American presidents are cut into the rock near the top of Mount Rushmore in the Black Hills.

VOA: special.2009.03.04

And so...what you're noticing is a fair mount of mergers and acquisitions, meaning less efficeint businesses are collapsing into biger businesses.

所以你会看到,企业间大量的,兼并，这意味着,工作效率低下的企业,会垮台，被更大的企业吞并。

普林斯顿公开课 - 国际座谈会课程节选