Canary in Coal Mine Concept
Palabras clave
canary,
coal,
mine,
concept,
warning,
signal,
danger,
environment,
pollution,
history,
early,
detection,
sensitive,
bird,
risk,
industrial,
safety,
toxic,
gas,
trend,
symbol,
awareness,
precaution,
health,
hazardous,
exposure,
animal,
indicator
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