There Pictures from outer space now show us how much land has ch

There Pictures from outer space now show us how much land has changed on earth．These images are taken by Landsat 7,a government satellite．The satellites have been used for 27 years．They reveal the clear-cutting of forests in the northwestern part of the United States．Pictures show the loss of rain forests in South America. NASA's Darrel Williams speaks about the Landsat 7 Project．He said that an eruption caused trees to burn up in a large forest．Fifteen years later,pinkish images from space show that the trees and plant life are growing again．Williams says that clear-cut areas easily show up in the pictures．He wants Americans to look at how much land is being cleared of forests in our country. Satellites have provided other information about changes on earth．In the past ten years,more than four miles have shrunk from glaciers in Alaska．Landsat 7 received these computer images of Glacier Bay in Alaska. Hurricanes Floyd and Irene have damaged the coastline in North Carolina．Runoff from farms and silt have gone into the．ocean according to satellite images．Loss of trees and forests have caused hotter summers in southern cities such as Atlanta,Georgia. The Landsat 7 images are like pictures in a photo album．Instead of pictures of the family,the album shows changes around the globe in the past 25 years. A new satellite,Terra,is going to be launched by NASA soon．It will be more advanced than Landsat 7 and will take important global pictures．Ocean temperatures and energy loss will be provided by Terra daily. Landsat 7 knows that Alaskan glaciers have shrunk because__.
A、sightseers have noted the changes
B、computer-animated views have shown the shrinkage
C、one of the glaciers was hit by a ship
D、the temperatures are much colder
【正确答案】：B
【题目解析】：根据文章中的描述，Landsat 7通过接收来自阿拉斯加的冰川湾的计算机图像得知阿拉斯加冰川的缩减情况。文章提到“In the past ten years, more than four miles have shrunk from glaciers in Alaska. Landsat 7 received these computer images of Glacier Bay in Alaska.” 这表明Landsat 7是通过接收和分析计算机动画视图（computer-animated views）来得知冰川缩减的情况的。 A选项“sightseers have noted the changes”表示观光者注意到了这些变化，但文章中并没有提到观光者参与观察或记录冰川的缩减。 C选项“one of the glaciers was hit by a ship”提到一艘船撞击了冰川之一，这与文章描述的内容不符。 D选项“the temperatures are much colder”提到温度更低，但这与冰川缩减的原因无关，实际上，全球变暖是导致冰川缩减的主要原因。 因此，根据文章提供的信息，B选项“computer-animated views have shown the shrinkage”是正确的答案。