Complex sentence: Its base level dropped from sea level to over 500 miles below sea level.It cut its bed down to several hundred miles below sea level at Aswan and 8000 miles below sea level at Cairo.
Split into simpler sentences: Its base level dropped from sea level to over 500 miles below sea level. Katie Macdonald It cut its bed down to several hundred miles below sea level at Aswan and 8000 miles below sea level at Cairo.