详细解释:n. 追踪者, 描图者, 描绘工具
【计】 跟踪程序
【化】 示踪剂
【医】 示踪器; 示踪物; 描记器
英语解释：
名词 tracer:
an investigator who is employed to find missing persons or missing goodsan instrument used to make tracings(radiology) any radioactive isotope introduced into the body to study metabolism or other biological processesammunition whose flight can be observed by a trail of smoke同义词：tracer bullet