●新课导入建议 通过以下问题的讨论，激活学生的背景知识，并导入新课。 1) As we know, there are some unexplained mysteries in the natural world such as the Yeti, the Bigfoot, the Grey Man and the Loch Ness Monster. Have you ever heard of or read about any other monster? Tell the rest of the class, if any. 2) How much do you know about Lake Tianchi? Where is it? How big/deep is it?