rindexradiotracer./rey-dee-oh-trey-ser/US // ˈreɪ di oʊˌtreɪ sər //放射性示踪剂,放射性核素,放射性抑制剂,辐射性示踪剂Definitionsn.noun · 名词1. Chemistry.›a radioactive isotope used as a tracer. Level 4More words in r →