Answer:
Poor drainage or improper watering
Explanation:
Water issues — either too much or too little — are the leading reason behind yellow leaves. In overly wet soil, roots can't breathe. They suffocate, shut down and stop delivering the water and nutrients plants need. Underwatering, or drought, has a similar effect.
A vaccine works by stimulating the immune system to produce antibodies without actually infecting someone with that disease. They trigger the immune system to produce its own antibodies as though the body has been infected with the disease. But a vaccine will not make someone immune to a disease, it will simply help the body be able fight the infection better.
Answer:
A- si la población está evolucionando
Explanation: