问答题
设计任务：请阅读下面学生信息和语言素材，设计20分钟英语阅读的教学方案。
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
aetivities and justifications
教学时间：20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：
The Three Gorges Dam
"Walls of stone to hold back clouds and rain"
Mao Zedong wrote a poem in which he dreamed of "walls of stone to hold back clouds and rain till a smooth lake rises in the narrow gorges".Now his dream has come true.The power of the Yangtze River，which is the world"third longest river，has been harnessed by the Three Gorges Dam.
The Three Gorges Dam，which is the biggest construction project in China since the building of the Great Wall and the Grand Canal，has been built to control flooding and provide hydro-electric power for the central region of China.The dam is nearly 200meters high and 1.5kilometers wide.It is the largest hydro-electric power station and dam in the world and has cost more than any other construction project in history.
Sun Yat-sen ，who was the leader of the 1911Revolution，first suggested the idea of a dam across the Yangtze River in 1919.Three quarters of China´s energy is produced by burning coal.In 1993，China used 1.2billion tons of coal for heating and generating electricity.Unfortunately，burning coal causes se-rious air pollution and increases global warming.The dam will generate electricity equal to about 40mil-lion tons of coat without causing so much air pollution.
The reservoir has flooded 2cities，11counties，140towns and more than 4，000villages.More than a million people who lived in the region have moved from their homes.Now they´re living in a happy new life in different areas.
The Three Gorges area is one of the most beautiful areas of China and the project has flooded some of China´s most famous historical sites，including the Qu Yuan Temple，the Han Watchtower and the Moya Cliff carvings.About 800historical relics have been submerged.Some of them are being removed and are being put into museums.