learning aims: 1. learn to make suggestions and list reasons in writing. 2. improve the skill of writing. important point: be able to make suggestions and list reasons in writing. learning guidance: 背诵积累预习案中的词组和句型，思考典题再现该怎么写。预习案previewing case 一 词组积累 1. take responsibility to do sth. 有责任做某事 2. arouse one’s interest 激发某人的兴趣 3. get involved in 参与；涉及 4.leave a deep impression on 给……留下深刻的印象
