The correct answer is a dichotomous key. Basically, you use the key to decide what species an organism is by looking at what traits it has, and if it doesn't have some traits you can instantly rule out a large number of species which brings you closer to your answer of what the species is that you're looking at.
Answer:
Revolution of earth around the sun
Explanation:
Closest I found was 'species that is harmed in a symbiotic relationship in which another species benefits - host'
Explanation:
Humus content is another characteristics
