[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 .