TOEFL Listening: TPO-TOEFL阅读TPO - 20R2G5P543I31D45N$

Symbiotic relationships involve the interaction of two or more organisms acting as partners A. Parasitic relationships involve the interplay of aggression by the parasite and resistance and adaptation by the host. B. Mutualism ordinarily involves an interaction between two members of the same species C. Mutualism is unique among symbiotic relationships in that it benefits both partners involved in the relationship. D. Parasitic damage to Australian rabbits was never reversed because the rabbits were unable to adapt to the parasites attacks. E. The rarity of commensal relationships stems from the difficulty of finding relationships that benefit one species without affecting the other F. The structure of biological communities depends on the types of relationships that exist among the species within