在九年级下学期的学习中，Unit 14是一个重要的单元。本单元的主题围绕着环保和可持续发展展开，帮助学生理解环境保护的重要性，并掌握相关的词汇和表达方式。以下是本单元的一些核心单词，希望能帮助大家更好地理解和记忆。

1. environment /ɪnˈvaɪrənmənt/ n. 环境

- The environment around us is changing rapidly due to human activities.

2. pollute /pəˈluːt/ v. 污染

- Factories are polluting the air and water in this area.

3. recycle /riːˈsaɪkl/ v. 回收利用

- We should recycle our waste paper to save trees.

4. waste /weɪst/ n. 废物

- Reducing waste is one of the best ways to protect the environment.

5. energy /ˈenədʒi/ n. 能源

- Solar energy is becoming more popular as an alternative to fossil fuels.

6. sustainable /səˈsteɪnəbl/ adj. 可持续的

- Sustainable development aims to meet the needs of the present without compromising future generations.

7. global warming 全球变暖

- Global warming is causing ice caps to melt at an alarming rate.

8. carbon footprint 碳足迹

- A smaller carbon footprint means less harm to the planet.

9. conservation /ˌkɒnsəˈveɪʃn/ n. 保护

- Conservation efforts are crucial for preserving biodiversity.

10. biodiversity /ˌbaɪəʊdaɪˈvɜːrsəti/ n. 生物多样性

- Protecting biodiversity helps maintain ecological balance.

通过学习这些单词，我们可以更好地了解如何采取行动来保护我们的地球。希望同学们能够在日常生活中实践这些环保理念，为建设一个更美好的世界贡献自己的力量。记住，每一个小小的改变都能带来巨大的影响！