Complex sentence: Modern civilian engines generally operate between 30 and 40:1, for instance, the three-spool Rolls-Royce Trent 900 used on the Airbus A380 has a pressure ratio of about 39:1.
Split into simpler sentences: Modern civilian engines generally operate between 30 and 40:1. The three-spool Rolls-Royce Trent 900 used on the Airbus A380, for instance, has a pressure ratio of about 39:1.