Answer: The food chain
Explanation: It is important to have a large number of producers and herbivores in an ecosystem because of the food chain. Without producers the herbivores would have no food. and without the herbivors the carnivores would have no food.
Answer: c is the answer
Explanation: it the answer because spud waves travel without the air u hear it
Answer:
The correct answer is prospective cohort study.
Explanation:
A prospective cohort study is a type of observational research used in epidemiology to establish relationship between exposure and outcome.
Essentially, investigators follow two populations (one exposed to the factor under study and one not exposed) over time until the outcome occurs.
With this type of research, incidence (probability of occurrence) can be calculated, because a timeline is present.