Answer:
Evaporation.
Explanation:
Most cases of dropping water levels are simply evaporation, usually caused by higher temperatures in warmer climates.
Answer:
Common examples of physical contaminants include hair, bandages, fingernails, jewelry, broken glass, metal, paint flakes, bone, the body parts of pests, or pest droppings.
Explanation:
I would say true. I say this because there have been times where scientists find out that there are better ways of performing experiments, or found that certain materials work better for certain tasks. (Especially true in medicinal fields!)
