The teacher designed a specific theme unit on renewable energy to engage students in environmental science.
老师设计了一个关于可再生能源的特别专题单元，以吸引学生在环境科学中的参与。
Students were required to complete a research paper on a specific theme of their choice.
学生被要求完成一篇关于他们自己选择的特别专题的研究论文。