2020春人教版八年级英语下册Unit7 拓展阅读训练

2020年新目标八年级下册Unit7 拓展阅读训练 — 扩宽视野，启迪心智 韩老师 A Probably you have seen photos of the Grand Canyon（峡谷）, the great valley in the desert country of Arizona. But you must go there yourself to feel its true size and beauty. The Grand Canyon is one of the greatest natural wonders of the world The Colorado River（科罗拉多河）formed the Grand Canyon over millions of years. Slowly, the river cut down through hard rock. At the same time, the land was rising. Today the canyon is 1.5 kilometers and 445 kilometers long. The oldest rocks at the bottom of the canyon are more than 1 billion years old. The width varies from about 200 meters to 29 kilometers across. The rim（边）or top of the canyon is about 2,300 meters above sea level on the South Rim, and about 3,000 meters on the other side. As a result, there are different kinds of plants and animals on opposite sides of the canyon. The South Rim is dry desert country. The North Rim has tall fores