The answer to this question is:
Light (sunlight), water, and carbon dioxide! Oh, and chloroplasts.
I'm thinking it might be fossil evidence. Hope it helps!
Incorporating basic life support, the first thing one should do is survey the scene. Look for any obstacles that will make the response difficult such as shattered glass, fire, etc. Second, call emergency hotline (usually it's 911 but it may differ from other countries). If you are a certified basic life support provider, then continue with the next steps. Next step would be checking the patient's airway, breathing, and circulation (ABC) by checking the if there is blocking the airway, or if the patient can breathe spontaneously, as well as the pulse. Next step would be assess if the patient as a cervical fracture as this should be handled carefully. If the patient is not breathing or has no/decreased pulse then proceed with doing CPR until help arrives.
The more the people, the more pollutant they generate which will pollute the the water.
