[tag=NN | lemma=","] [lemma=fire] □
[tag=NN | lemma=","] [lemma=fire] □ □
[tag=NN | lemma=","] [lemma=fire] (□ | □)
Such aerosol payloads have included smoke , obscurant , fire retarding agents , crowd control agents , dye indicators , chemical / biological agents , and the like .