【正文】
years ago when massive glaciers melted and caused the sea level to rise several hundred feet worldwide. 23 Geologists believe that the Bering land bridge, over which human beings are thought to have first entered the Americans, disappeared about 14,000 years ago when massive glaciers melted and caused the sea level to rise several hundred feet worldwide. 24 Geologists believe that the Bering land bridge, over which human beings are thought to have first entered the Americans, disappeared about 14,000 years ago when massive glaciers melted and caused the sea level to rise several hundred feet worldwide. 25 Geologists believe that the Bering land bridge 000 years ago when massive glaciers melted and caused the sea level to rise several hundred feet worldwide. 26