单击此处编辑母版文本样式第二级第三级第四级第五级必修4立体设计·走进新话题A Trip Along the Three Gorges(一次三峡之旅)功能Talking about obligationpermission and prohibition(谈论义务允许和禁止)语法Revision of modal verbs(复习情态动词)重点词汇及拓展1.colleague n.同事2.dow