isotopeKK [ˋaɪsəˏtop] /ˈaɪsəˌtoʊp/发音名词1同位素Carbon has several isotopes, one of which is used for dating fossils.碳有好几种同位素,其中一种可用来测定化石的年代。2放射性同位素医学Doctors inject a small amount of a radioactive isotope before the scan.医生会在扫描前注射少量的放射性同位素。用这个字练口说→