Both measures expand coverage under Medicaid, the existing government program servicing low income Americans, between 133 and 150 percent of the government's official poverty level, for the Senate and House plans respectively.

VOA: standard.2009.12.25

You could imagine a protein that's existing inside a cell at some level of abundance.

想像一下,在细胞中有一种大量存在的蛋白

耶鲁公开课 - 生物医学工程探索课程节选