Trace Nb微量铌tracen.痕迹；微量；踪迹v.追踪；描绘；找出根源Trace Impuring Elements锆合金trace evidence at scene现场痕迹traceback attack source攻击源追踪Trace element detection微量元素检测Trace poisonous e ement痕量有毒元素trace moisture analysis微量水分分析trace hazardous element微量有害元素trace element of zircon锆石微量元素Trace elements/blood痕量元素／血液trace organic pollutant微量有机污染物