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tracer (element)的英文翻译是什么意思，词典释义与在线翻译：
英英释义
名词 tracer:
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an investigator who is employed to find missing persons or missing goods
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an instrument used to make tracings
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(radiology) any radioactive isotope introduced into the body to study metabolism or other biological processes
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ammunition whose flight can be observed by a trail of smoke
