Assertion: hydrogen sulfide's concentration | /r/HasProperty | about 0.0001-0.0002 ppm
Facets:
Source sentences:
text: Normal average concentration in clean air is about 0.0001-0.0002 ppm.
text: Normal average concentration in clean air is about 0.0001-0.0002 ppm.
text: Normal average concentration in clean air is about 0.0001-0.0002 ppm.
text: Normal average concentration in clean air is about 0.0001-0.0002 ppm.