Is there any optional answers?
This could be two answers Water or Oxygen. I would go with water because it contains oxygen therefore making it a possible answer. Hope I helped. :)
The only competitors that humans have for food are other humans and insects: Agree; we do compete with other animals for food
<u>Explanation:</u>
The term competitor is used to describe interaction that takes place within any two organisms as a result of which both the organisms are affected. The functional role that an organism have within the environment is known as Niche.
Parasitism refers to the interaction that takes place between any two organisms or species as a result of which only one will get benefits and the other one will be getting affected.In an ecosystem, every organism strives hard for living and need food for its survival. Hence, the competitors for food in an ecosystem will be other human, insects, animals, etc.
