An example would be acid rain because acid is a chemical.
Poliomyelitis or Polio, a virus and viral disease. Poliomyelitis while relatively common and asymptomatic, had a high prevalence of paralysis due to the sheer number of infected. The vaccine was created by Jonas Salk, that immunized the patient towards the disease, saving countless lives, and effectively paved the way to eliminating polio in US.
A. Troposphere
Is the closest around plane flying level
Answer:
A chromosome consists of DNA and genetic organic molecules.
