知识贝壳
知识贝壳
所属栏目：英汉双解化学
1. The relative amount of agiven element among others; for example,the abundance of oxygen in the Earth’scrust is approximately 50% by mass. 2.The amount of a nuclide (stable or radioactive)relative to other nuclides of the sameelement in a given sample,T ......（本文共 622 字 ） [阅读本文] >>