前後 - ( )

Las Vegas, Nev. In some of the oldest satellite imagery available in Google Earth, Las Vegas's wild growth is clear. The older image, from 1950, shows no traces of what would become one of the fastest growing U.S. cities during the second half of the twentieth century. All that stays the same in the two images are the two roads -- though many lanes were added by 2013. Screenshot: Google Earth; Mashable composite