设计任务：请阅读下面学生信息和语言素材，设计一个25分钟的听力教学活动。 教案没有固定格式．但须包含下列要点： teaching objectives teaching contents key and difficult points major steps and time allocation activities and justifications 教学时间：25分钟 学生概况：某城镇普通中学高中一年级学生，班级人数40人。多数学生已经达到《普通高中英语课程标准(实验)》五级水平。学生课堂参与积极性一般。 语言素材： Why do earthquakes happen? Scientists explain that the outside of the earth is made of a number of different plates. At San Francisco, the Pacific plate which is moving towards the northwest meets the North American plate. The Pacific plate is moving very slowly--at 5.3 centimeters a year. Sometimes these two plates stop and do not move for years. Then suddenly, they jump and an earthquake is felt. As a result of the movement of these plates, California has always had a lot of earthquakes. When the 1906 earthquake happened, the Pacific plate jumped 5-6 meters to the north. China also has an unlucky place on the earth. The Pacific plate is also pushing on China from the east as the plate moves west. Likewise, the Indian plate is pushing on China from the southwest as that plate moves northeast. The same power that produced the great Himalayan Mountains now causes earthquakes in China. We cannot stop earthquakes, but we can do things to make sure they do not destroy whole cities. First, it is not a good idea to build houses along the lines where two of the earth's plates join together. Second, if you think there may be an earthquake, it is better to build houses on rock than on sand. Third, you must make the houses as strong as possible. Weak buildings will fall down in an earthquake, but strong ones may stay up.