What is the purpose of the 1st paragraph?What is the topic sentence of the 2nd paragraph?Summarise the last three paragraphs in one sentence.Translate the last sentence in the last paragraph.

• 提出问题是为了让学生更好的了解内容，总结是为了培养学生的高度概括能力，翻译是为了培养英译汉的流畅性。