摘要
Biotrace element is a developing frontier, of which the main object concerns the relationship between the trace element, and health. Because of the antagonistic and synergetic effects, it is always necessary to take the different kinds of elements, not only one, into account in the research work. At present, the statistic remarkable test is used popularly, which shows whether there is any relationship between a trace element and the disease and, if there is, then how close the relationship is. Unfortunately,
