Answer:
The different species present in an ecosystem make the ecosystem balanced. The species of an ecosystem interact with one another in one form or the other. For example, the presence of a plant species will provide food for the abundant types of herbivores present in an ecosystem. A predator might feed on many types of preys. Hence, the presence of different preys will reduce the chances of a species from becoming wiped out from the ecosystem. Hence, all the organisms in an ecosystem are dependent on another in some way or the other.
Hazardous substances are dangerous substances while toxins are poisonous substances. Hazardous substances may cause harm to an individuals health; they include acute toxins such as cyanide; substances harmful after repeated or prolonged exposure such as mercury and silica, among others. Toxic substances can be poisonous or cause health effects.
Answer: D volcanic eruption
Deletion is the correct choice