Carbon monoxide is a good tracer for moving smoke plumes, even across large distances.
一氧化碳可以用来追踪烟尘羽的移动情况，即使经过遥远的距离。
2
The isotope tracer method presents the advanced method of carbon isotope, nitrogen isotope, oxygen isotope and Pb tracer.
同位素示踪法着重阐述了较先进的碳、氮、氧和铅同位素的示踪。
3
Conclusions the activated carbon can be used as a useful lymphatic tracer and drug carrier, for it is characterized by avirulence, high lymphatic tropism, long residence time in the lymph nodes.