trac·er /ˈtresɚ/
 追蹤者,描圖者,謄寫員
 trac·er /ˈtresɚ/ 名詞
 掃描器,故障檢尋器,示蹤物,追蹤物,追蹤者,失物追查單,同位素檢查器,描圖員,描圖器,仿形器,曳光劑,曳光彈
 tracer
 追蹤器
 tracer
 追蹤器
 Tra·cer n. One who, or that which, traces.
 2. A person engaged (esp. in the express or railway service) in tracing, or searching out, missing articles, as packages or freight cars.
 3.  An inquiry sent out (esp. in transportation service) for a missing article, as a letter or an express package.
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 tracer
      n 1: an investigator who is employed to find missing persons or
           missing goods
      2: an instrument used to make tracings
      3: (radiology) any radioactive isotope introduced into the body
         to study metabolism or other biological processes
      4: ammunition whose flight can be observed by a trail of smoke
         [syn: tracer bullet]