精选优质文档-倾情为你奉上Elements of LifeThe creation of life requires a set of chemical elements for making the components of cells. Life on Earth uses about 25 of the 92 naturally occurring chemical elements, although just 4 of these elements-oxygen, carbon, hydrogen, and nitrogen-make up about 96 percent of the mass of living organisms. Thus, a first requirement for life might be the presence of most or all of the elements used by life. The word “components” in the passage is closest in mea
