1. Modal verb for suggestion: "should definitely be" uses the modal verb "should" to express a strong recommendation, which is a common way to talk about goals or priorities in IELTS Speaking.
2. Parallel structure: The list "reducing pollution and waste, promoting recycling, and investing in green energy sources" uses parallel structure, making the answer clear and organized.
3. Present participle as a subject: "By preserving nature" uses a present participle phrase to introduce a reason or result, which adds variety to sentence structure.
4. Present simple tense: The answer consistently uses the present simple tense (e.g., "we ensure," "it benefits") to talk about general truths and ongoing responsibilities.