1.Noun phrase as subject: "Humans have an ethical responsibility to protect animals" uses a noun phrase as the subject, showcasing a complex sentence structure.
2.Infinitive phrase as adverbial: "to protect animals" functions as an adverbial, explaining the purpose of the ethical responsibility, adding depth to the sentence.
3.Contrastive structure: "not just about preserving species; it's about fulfilling our moral duty" uses a contrastive structure to emphasize the broader implications of protecting animals, enhancing the complexity of the answer.
4.Relative clause: "that we enjoy today" is a relative clause providing additional information about the "rich diversity of wildlife," demonstrating advanced grammar usage.